You really expect people to reply in 15 minutes??!!
If you want lots of responses you need to wait a couple of hours til America comes on line
In the mean time:
You could be right. If you are
sure that she likes you then there is a fairly high chance that she wanted to find out whether or not you like her back. This could've been a spur of the moment thing, or premeditated.
On the other hand... girls flirt a lot without really liking the guy. Especially teenage girls. And especially if they know the guy likes them. Attention feels nice. She may be genuinely confused why you sent her this picture. You may actually look funny in it. She could really be embarassed
I don't know the girl: I can't give you a definite response