Don't know if you got your answer but I believe it's a quote of her words from "Project Runway" which she hosts. I believe the quote goes "one day you're in, the next day you're out" or something like that.
why does "you're in or you out" (?) describe Heidi Klum? Sorry, I'm not american and don't really get all those country-special jokes, puns and, well, informations. Can anyone help out?