Ever kissed a rake? Of corse not, you'd look stupid. Much the same can be said of a rake face, one who is so ugly/stupid/other that to be seen kissing it, would be like seen snifing your mums undies.
Ally McBeal is a rightrake face, man, gimmie ten minites with a hammer!
To get a rake in your face is to be turned down when you ask someone out. When one thinks about it, one would say that the image is good to represent the feeling felt when turned down, which is similar to that of stepping on a rake, it's embarassing and hurts :)