I mean, how is it any different than referencing movies, music, TV shows, stand-up comedy, or any other piece of pop culture?
Would referencing a movie somebody hasn't seen before make you terminally in-theater or something? Though, having said that, I am now going to take every opportunity I can to work the phrase "terminally in-theater" into my daily life anytime somebody mentions a Marvel movie or something.
For those who don't get the joke, bagels are a Jewish food.
Also, I'd argue they got a good thing going there. Got the gravlax, bagel, and egg on top. Sounds like a delicious breakfast sandwich to me (just get rid of the silly kebab spear and give me some fruit on the side or something).