@reginasbread, I stumbled across an interesting explanation for that. So, there are four aspects of attractiveness: beautiful, hot, cute, and handsome.
Beautiful is pleasing to look at. Hot is sexy. Cute is someone (or something, think of a kitten) you'd like to take care of. Handsome is someone you'd like to take care of (be cute towards). This was taken from a thread from eigenrobot from Twitter, but I see it making sense.
Hence, “attractive but not beautiful” could be someone high on hot but not necessarily high on beautiful. And that's fine.
However, one thing to remember is it's personal (albeit, there is a certain distribution of standards across any group).