Girls dress for other girls

First I need to preface this by telling a quick story about how I came to learn of this phrase.  I was at work flipping through a mag, maybe GQ or Rolling Stone, and there were a few pics of Scarlet Johansson who I think is smoking hot.  Anyways, I mentioned to a female coworker of mine that I thought so and asked her whether she felt the same way, or something along those lines.  She said that the she thought she was 'guy hot!'  I was completely dumbfounded.  Had no idea what that meant and asked her so.  She couldn't come up w/an explanation or an example.  So I cited other attractice women ( in my eyes) like Angelina Jolie and Megan Fox as examples.  The answer was still 'guy hot.'   So all of a sudden I had to wrap my head around 'guy hot' and 'girl hot.' 

Now, I was really struggling to wrap my head around the concept.  The next few days I continually pestered my coworker for a definitely or an example, but she couldn't come up w/one.  I asked a few other coworkers, both guys and girls, to no avail.  Finally, I asked another coworker who shined the light on the whole thing w/one simple phrase, 'girls dress for other girls.'  AHA!  Actually, I still didn't understand immediately until she explained that 'girl hot' meant that girls dressed to impress other girls.  To look cute, to get compliments, to look chic, etc.

My world was turned upside down that day.  I have gained an edge, a leg up on the famously mysterious mind of the female.  Guys....not all girls dress to impress us.  How bout them apples!