I was looking at the male player one.
At first i was thinking "Why does my male character has bouncy breasts physics?", but then a once-you-see-it-you-can´t-unsee-it moment happened and the collar (which has almost the same color as the head) turned into a jaw. The eyes of the player character are pretty low and the face is very round, so in my mind the head extended to the yellow collar. I have made a photo. Imagine the triangular shadow under the characters head as a mouth, that opens and (almost) closes during the idle animation.