For the Game Center article, my friends Game Center screen is different with no plus sign, why?

[iMore Question]

For the Game Center article, my friends Game Center screen is different with no plus sign

Ok so her screen is blue and different all around, there is no plus sign at all!!!! I need to friends her but, how can I do that- it also won't let me friend her, she has even showed me her Game Center screen! Help please!!!!