My understanding is that when women wear bodysuits they need not wear panties.  I am also told that men in bodysuits also not wear any underwear.

So why does she have those striped panties on?  

I love this picture, though, especially if you notice how her pink bra and black panty is hanging on the door knob on the right.  Every time I walk into a woman's room and see undies lying around, it turns me on.