And can any of those effects take bold lines and make them appear have sharp 90 degree turns like what was seen in that flag?
Well, a copy machine is kind of a camera, and I know some documents that would be troublesome if duplicated by nefarious actors (checks come to mind) have a feature that causes the word “COPY” to appear on the copy. It can’t be seen on the original.

a feature that causes the word “COPY” to appear on the copy. It can’t be seen on the original.
Can they also take something that is seen in the original and make it not appear in the duplicate? Remember, that swastika doesn’t just have added red perpendicular lines, but parts of the red stripes are also missing.

Can they also take something that is seen in the original and make it not appear in the duplicate?
Beats the fuck out of me.
I saw it first in this picture
link
and my first thought was that the swastika was a bad photoshop. So, it wouldn’t surprise me if it WAS a prank based on camera artifacts. There’s something odd about that picture, and it’s exactly the sort of prank I can see someone doing to a Republican congressman. Seems far more likely than a congress staffer going through the trouble of finding a swastika flag and then putting it up prominently in their office.
What does surprise me is that nobody can find these magic flags for sale anywhere.
Not commenting on the actual flag event and the actual congressman, but just thinking on the general idea.
We’ve all seen those images covered in finely ridged plastic that display 2 or more images as you tilt them back and forth. It’d be trivial for somebody to manufacture those that showed two unrelated flags.
Which could either be designed so both are equally visible alternating as you tilt, or such that one image is visible from almost all angles, and the opposite image is available only from one particular narrow and unlikely angle. Call it the “secret” image that only insiders who know the trick can reveal.
That’d make it real easy for a camera to take a pic that appears innocent, when the notso innocent secret reality is actually there to be seen (or photographed) if you know exactly where to stand to reveal it.
Lenticular displays. But such images would be visible to both eye and camera if in the right position, and “invisible” only at slightly different viewing angles. Most lenticular items are made so that two human eyes will see different images, giving a 3-D effect.
The whole notion of an item that has a hidden image that only cameras (still or video) can see is patent nonsense.
That said, the image above looks to me like it could be photoshop.
Could be photoshop, except they’re not denying it was actually there.
They’re denying that the staffer was aware there was more than a regular flag there.
At minimum (which is still below the believability threshold) in the age of Zoom meetings that began several years ago, I’d expect any staffer, especially a younger one who is more comfortable with such technology, to know to have their self-view on, so they can see if they’re not wearing pants or if there’s something odd in the background visible to any other meeting participants.
You know….like a damned swaztika right behind their head. His brain probably didn’t even register it as something wrong.
Mysterious packages were sent to Republicans, and rather than have said packages checked out by authorities, instead they decided to open the packages and display the contents on the wall right behind them, unobstructed, in full view of the camera? I have to admit, claiming dumbfuckery is rather refreshing…but not very believable.

Lenticular displays. But such images would be visible to both eye and camera if in the right position, and “invisible” only at slightly different viewing angles. Most lenticular items are made so that two human eyes will see different images, giving a 3-D effect.
But most such images are pretty clearly different from just a normal printed flag. The lenticular layer feels quite different, usually have clearly obvious ridges, and being thicker and stiffer than anything you’d use for a “flag” type of thing. There’s no way you’d get all the way through putting that up on our wall and not notice something odd about it, even if you don’t spot the hidden image.
And then, this “hidden image” can bee seen by the camera, which is looking almost straight at the flag. That’s probably the most common angle anyone would look at it, and so why didn’t they see it? I could see someone missing the hidden image if the only angle it could be viewed at was at a large angle to the plane of the flag, but that’s not what we see here.

Mysterious packages were sent to Republicans, and rather than have said packages checked out by authorities, instead they decided to open the packages and display the contents on the wall right behind them, unobstructed, in full view of the camera? I have to admit, claiming dumbfuckery is rather refreshing…but not very believable.
Probably sounds better than saying “Oh, yeah, the Young Republicans of New York sent us this free flag” (or whatever set of donors) and throwing them under the bus.
So this guy didn’t already have an American flag until some stranger sent him one? How unusual; you’d think he’d bring his own and it would be the first thing he hang on the wall.
Admittedly its a blurry screen cap, but from the images I have looked at the flag appears to be purposely altered.
Where the field of the swastika crosses the red stripes of the flag there are two rectangular shapes that are a slightly different white than the white stripes of the flag. You can even see slight colour difference where the patches cross the red stripes and shadowing that suggests a physical edge to the apparent patches. Maybe those are just compression or some other artifacts. Maybe.
The flag is mounted on a plastic pole/frame and curtain folds are plainly visible. It appears to be a fairly typical light nylon flag, not some thicker poster board or paper. I would expect some previously undemonstrated ‘trick’ image tech to more likely be printed or presented on a substrate other than light fabric.
It looks like somebody in a moment of edgelord frat humor altered an existing cheap nylon flag.

And can any of those effects take bold lines and make them appear have sharp 90 degree turns like what was seen in that flag?
No but they can take a LOT of fine little lines and make them invisible until matched with a Moire filter of similar frequenc.
I don’t know why you bring up right-angle lines. Making patterns with right angles are no challenge at all. Just look at the lettering in the examples I linked tp.

Could be photoshop, except they’re not denying it was actually there.
They haven’t denied it so it was there.

It looks like somebody in a moment of edgelord frat humor altered an existing cheap nylon flag.
Yep. It appears to me to be squares of white paper with red ink applied to alter the flag and those were affixed. Not photoshop since they haven’t denied it was there and are now saying it was a “magic” flag.
Basically IOKWARDI but with an extra step

I don’t know why you bring up right-angle lines.
Where did the vertical parts of the swastika come from? Suggesting this is a random video effect means said effect needs to be able to rotate 4 specific sections of the US flag by exactly 90 degrees.

Making patterns with right angles are no challenge at all.
And you’re saying that could happen, by accident, and to only this one flag?

Just look at the lettering in the examples I linked tp.
I’m not seeing it in the first link and the second one isn’t working for me.

Where did the vertical parts of the swastika come from? Suggesting this is a random video effect means said effect needs to be able to rotate 4 specific sections of the US flag by exactly 90 degrees.
Random? I;’m talking about a deliberately made effect. Where did you get the idea that it was fortuitous.
I’m not saying that this IS what is occurring in this case. I’m saying that this is how you can create the effect. Only it won’t work for all distances and magnifications. In short, I sure as hell don’t believe that it’s happening here.

Where did the vertical parts of the swastika come from? Suggesting this is a random video effect means said effect needs to be able to rotate 4 specific sections of the US flag by exactly 90
It doesn’t need to “rotate” anything I just needs to make two patches of that are red in person appear white on camera and two patches that are white appear red. As to whether that is possible without there being something obviously weird about the flag in person still has yet to be established.
Ya know what, it doesn’t matter. We’re spinning our wheels trying to come up with some way to make their bullshit excuse true. It’s just a distraction.
He’s got a flag with a swastika on it. Period.