Well, technically Wyandottes are supposed to have rose combs as well... I do have a couple that don't, but they are supposed to. So, that can't be the differing (sp?) factor.
Personally, the brown chick doesn't look like a GLW to me, I have 19 babies in my livingroom, and they don't look anything like that. I do, however, agree on the SLW, for the black chick.