Saw this, and didn’t know what to do!
Go ahead and buy the Pepsi.
For 50 cents? Hell yeah.
Cute - in old days, that trick was done by setting the aperture (f-stop) to widest open (lowest number) - this produces the “flat”, 2-dimensional effect.
But, even with a flat photo, you can see the depth - a car lane in front and back, the Pepsi machine, whatever the red things is - all are there and can give you a sense of depth that the photog deliberately removed.
What trick? There’s no trick. It’s a picture of a door with “Do not enter” in red under “Enter” in blue. Walmarts have this on the inside of the entrance doors. It would make more sense if it said “Do not exit.”
The Do Not Enter sign appears like it could be on something inside the door.
And the Walmart signs are not both on the same side of the door, so there is still a trick if this if you are seeing the back of a different door.
The Enter and Do Not Enter signs are on the same side of the same door. I know because I just posted a similar photo on Facebook. I have observed this at every Walmart I’ve ever been in and also found it amusing. If Enter were only on the outside of the door, you would just see the blue background, or maybe “retnE” from inside.
Is your name Stanley? If not, you’re welcome to enter. 
I’m always in the mood for a refreshing DP.
You have it exactly backwards. Narrowest aperture (highest number) produces the flat, everything-in-focus effect. Unless I’m completely not understanding what you mean by flat, 2-dimensional effect.
I would make a point of asking the manager of the store what to do. Also tell him that I was stuck at the door for 2 hours deciding what to do!
I’ve asked them similar questions. Like if there is a sign saying “Shirts and shoes required”, I will ask if pants are required too. 
You made the right choice. But how did you get free after 2 hours? Does being pants-less help that situation or do you reserve the no-pants rule for the “shirts and shoes” situation only?
Just this past weekend I saw a sign on a road right next to an outlet mall that said “NO OUTLET” and I wondered if that would confuse folks.
Push… No, pull!
Do Not Enter is just a suggestion anyway. I don’t let signs tell me what doors not to use.