Depends which way they're facing.....

Seriously, unless there is something overwhelming prominent about her (two heads, wooden leg) I think we all automatically (and remarkably rapidly) do a whole person scan and then check the face. We now have enough information on whether this is a a) a female and b) a potential chance, even a remote chance.

Now we're free to indulge our fancies and check out the bits that attract us most. But we only do this after we know more-or-less what we are looking at. Really striking and magnetic women somehow grab our attention during the subliminal scanning phase. They have the MAGIC!