And, why is it okay to assume that two friends would dress exactly alike and then to assume that because one seems a little more put together on a given day that there is a "reason" for it?
Our daughters are very different: my younger one is more fashion conscious than my older one, with the younger looking trendy even around the house, where her older sister has on jeans, t-shirt, pony-tail and feels like she is lookin' good and good to go (which she most certainly is IMO)! But they are the best of friends with a thousand common interests other than clothes, shoes and hair styles.
So, I agree that I do not find anything telling in what Abby is wearing and I think she looks totally casual anyway.
I think that reading too much into the word "hike" can cause a misunderstanding as to the appropriateness of dress in this case. The girls were
"hiking around" which is very different from an actual hike.
The girls went here often, probably crossed that bridge often. It is known to be a popular spot with the teens in the area.
They were dropped of for a few hours of "hiking around" and taking pictures. So, again the mode of dress for
either girls was appropriate.
JMO, of course.