I have noticed one of those pictures that, depending on how tricksy a mood your mind happens to be in, looks like something that it isn’t.
It is on the BBC news website (Under the ‘Also in the News’ section, and titled ‘Wii-type games linked to sprains’. I’d link to the article itself but then the picture would be too big and the effect probably wouldn’t manifest itself) …
Here is a picture of it on it’s own in case the above link updates and it goes away.
When I glance at it or see it for the first time (upon each visit to the site) I see it as…
A woman facing [my] left, holding her boob and a bit of fabric
But what it actually is (in case you are ONLY able to see what I’m seeing) is…
A woman facing right, holding her shoulder
In case you’re wondering why I spoilered those - it’s so you can look at the images without prior information about them and let your brain perceive them freshly.
I suspect I will be in the minority of people seeing what’s not there.
The hand is cupping it so the hand is obscuring the ‘roundness’. If you’re seeing boob you [r brain] seems to ignore the parts of the image that don’t fit the logic of a woman facing left cupping a boob.
Her hair (which is on her front) is seen as being on her back.
And when you’ve seen the right-facing shoulder-holding picture your brain has enough information to make it difficult to switch back to the left-facing boob-cupping picture.
In other words if you’re having a hard time seeing boob it’s because it’s too late. your brain has correctly interpreted the image.