"All things being equal" was meant to be the former -- if you have two teachers with the same looks, will they look more attractive teaching subject A or subject B. Admittedly, though, stereotypes of what various subject teachers usually look like creep into our ratings. I know attractive romance language teachers; I don't know any attractive chemistry teachers.

After further discussion with people, I feel I need to defend my selection of English as an attractive subject. I chose it because I have heard of a lot more english teacher-student romances (most with a male teacher) than I have with other subjects. I think english is especially attractive in high school, where these innocent teens have the opportunity to talk about love and whatnot in class for the first time.