I usually see both pretty quickly.
Mt. Rushmore: Three surveyors and some other guy.
Life goes on within you and without you. -Harrison
Hear the echoes of the centuries, Power isn't all that money buys. -Peart
After you learn quantum mechanics you're never really the same again. -Weinberg
I see the white part of the image as the object first in all of them. But I can see the other image easily, at will. Except the last one. I only saw the young woman, and it took quite a concerted effort to pick out the old woman.
Looks like race baiting to me.
I see the chess piece picture as chess pieces. I see the figures but the chess pieces always look real.
I can not flip the last one. I can't find the old crone and I have seen the picture before and know that when
I do see her it will be difficult to flip back to the girl.
Am I stark ravin' bonkers?