Yes, this is Mika's crate criteria! She has to have at least her two back paws in the crate. When we started playing Crate Games last winter this is what she offered me, and I didn't want to correct her (I never correct Mika), so this is what she's allowed to do. She doesn't try to go farther than this anyway before I release her. In this photo I didn't even tell her to go in the crate -- she went in on her own.
No photo of Wall-e's crate criteria, but he has to have his whole body in the crate, and no part of it can stick out, including his head. He's not soft like Mika so he can learn with corrections (by corrections I mean closing the crate door if he sticks his head out, nothing else).
How about Shadow? Well, in her view, her crate criteria is "get out as fast as I can, hissing and scratching!" To Shadow, a crate = going to the vet and suffering the disgrace of a checkup.