My brain won’t let me get them to go back the other way!
It’s the smaller one on the far left, it works a treat as well.
To get them to flip back, squint your eye so that they appear foggy. look at the largest circle and the square tray. They seem to be the easiest to flip. (referencing flipping them back to a bottom up position)
I literally just glanced at the smaller one on the far left of the picture and they all turned, maybe I’m just very suggestible… 
I think they are all the same. For me it’s the one on the bottom, slightly lighter than the rest of them.
This is very interesting, I scrutinised them all, then stared at the one on the far left again, and again the others had no effect but this one instantly turned them all? Perspective can be fascinating…“what a piece of work is man”.
Ok the top left plate worked as well if I looked into the top left-hand corner of it, this might be related to which side of my titchy tiny brain has dominance?
The smallest far left bowl flips them for me everytime. Then I read they’re upside down and 
they’re upside down 
I’m very suggestible sigh
“Look into my eyes! You like monkey feet. You like monkey feet.”
I must be weird, because I can pretty much flip them back and forth at will. Then again, I’ve always been able to do that with those types of optical illusions.
Well, personally I prefer pickled monkey feet…
Edit to taste no evil
That’s a dumb analogy. Penguins swam. It’s the Kangaroos and Koalas that put a cog in the flood story. Yeah, they can both swim but they’re gonna not gonna make it much further than a mile off the coast. On the other hand, if they managed to grab hold of a penguin and hold on tight, they just might make it. Do you suppose there was a giant penguin exodus? Millions of penguins swimming towards Noah’s Ark, and only the first two to arrive made boarding call?
