I suppose... if one were to be completely literal... the reflective part is behind the glass, and you do have to look "into" it, when you think of it that way. Tbh though, I think either usage is fine.

by Anonymous 14 years ago

I think you look into it; your eyes go into different focuses looking at yourself rather than looking at the physical surface of the mirror.

by Anonymous 13 years ago

That's like saying you don't look THROUGH the window, you look AT the window.

by Anonymous 13 years ago