This. Is. HILARIOUS!
I can't stop laughing because it's so off-the-wall hysterical! Especially the welcome sign with Celestia as the stereotypical stern tyrant that's so bantered about in the fandom!
I'm thinking of an MLP:FIM crossover of my own where my own original characters Ricki Lee and Tony are on a day trip to Equestria from their home in Honolulu, Hawaii. It would be a magic portal/border crossing off a real-life Honolulu highway and include a sign like the one in your story, but with the usual smiling Celestia. Ponies cross over into Hawaii for pineapple muffins (especially Derpy) and shave ice, including Celestia herself. Ricki Lee & Tony's family have stopped at the portal to hang out and talk to the ponies before crossing into Equestria. It's a cute and whimsical piece.