30 Rock + TV Tropes
↳ ’Celebrity Paradox’ #1:
A Celebrity Paradox describes the complications that arise from creating a fictional universe in which aspects of another universe (either fictional or real life) do not exist. For example, taking an actor well known for a certain role, and putting them into a completely different role, or erasing a well-known fact from the real world as to remake it to fit their story better.
In modern updates of a work, or in one that is completely separate to it, the original may be unheard of (for example, in 30 Rock, Saturday Night Live does not exist, as TGS With Tracy Jordan is that world’s equivalent, and because Tina Fey was a well known cast member/writer on the show beforehand). Writers get a little kick out of toying around with the concept though, such as having the character meet the actor/actress playing them, or giving a shout out to the original source.
(In 5x22, Liz wonders who played “the white guy in Invictus” - it was Matt Damon, who played Liz’s boyfriend Carol in multiple episodes earlier in the season.)