Can be as simple as body language or tone of voice that you might not be self aware of, and we certainly wouldn't be. Maybe you checked her out too obviously before hand and seemed like a creeper? Or maybe she's just reacting to being "hit on" by someone she wasn't attracted to. Or you weren't the first to ask for a photo lol. Lots of possible scenarios that you (and us) just aren't aware of.
And don't message her about maybe being weird. That's weird.
And don't message her about maybe being weird. That's weird.