Seamus's physical type is short and big, especially with red hair.
However, he also is attracted to people he loves, and repusled by people he dislikes. So while I'm not his type (while neither tall nor thin, I'm taller and thinner than his type), he's definitely extremely attracted to me.
So I don't feel any negative emotions about it. If he obviously wasn't attracted to me, I might feel bad that I'm not his type. As it is, I only noticed because he kept being attracted to the same kind of females, and I don't look like any of them, so I was surprised.