By definition, asexuality is either a lack of attraction, or a low level of it. You could still be considered asexual, if it is a low level of attraction. I myself am bisexual, so I should not be considered an authority on asexuality. It'seems hard to tell if you are looking for a label, or just trying to sort out your feelings. I hope I was able to help a little bit, good luck sorting things out!
Do you feel the need to fuck the person or do you just find their appearance nice to look at? If the former, you're probably not asexual. If the latter, you just find them aesthetically pleasing and that's normal.
If you're a guy who gets attracted to girls at all, you're straight. If it's that slight, then the term a friend of mine uses for himself is "straight with asexual tendencies". Take that for what it's worth.
Its okay to be attracted to the appearance of a person but it doesn't mean you actually like them. If it's really sticking to you like always on your mind... my friend you might not be asexual but I don't think that is the case her. Nothing is wrong with being asexual and being attracted to someone else..its human nature t doesnt mean you actually love them.