As they continue watching the show, she finds that the show has became so strange to her, that it makes her "question the concept of reality", causing her to get upset. Marge then asks her to go outside to find some real horses.
From the dialogue used by the purple horse on the television show, Marge and Lisa were watching Andywilson92's remake of a clip from its first episode, where Twilight Sparkle says "I heard you're supposed to be keeping the sky clear. I'm Twilight Sparkle, and the Princess sent me to check on the weather". This quote was distorted by Andywilson92.