The question then is, are those panties, or something else, like a ruffle in her dress or a ribbon?
They do look like panties to me, though. Some sort of string-style, judging by the lack of anything visible on her hips. If you follow the edge of her dress, it ruffles up and away. So, yeah, think they're just weirdly drawn panties.
Removing from the pool, if no one else did while I was typing.