I can't decided if these two were my favorite Portal cosplayers! They seemed pretty into it! And that's always really fun. I love the Wheatley! And I think that glass skull is a reference to when GLaDOS told Chell she's going to laminate her skeleton when she dies and pose it in the lobby (so future generation can learn not to have her unfortunate bone structure). But I could be wrong!
The GLaDOS is
. And it turns out that crystal skull is Cave Johnson's skull.