Add someones photo to address book contact?

I'm trying to add a photo I have of a friend to their entry in my address book.

I'm presented with a photo chooser which appears to only allow:

1. System Defaults (i.e. NOT their picture)
2. Camera (a photo that would require them to be sitting directly in front of my computer)
3. Photos (which appears to only allow me to choose those my iPhone has physically taken, which would require I be in their direct presence
4. Photo Both (see option 2)

I can't seem to find a means to add a photo a person has sent me.

Is there a way to add a photo without having to be in the direct physical presence of a person?