The rhyme comes from My Little Pony: Friendship is Magic, where Princess Cadance was Twilight Sparkle's foalsitter when Twilight was a filly. Their sunshine chant, complete with hoof clops and a little shake, is shown as a childhood ritual they both remember years later, notably around A Canterlot Wedding in 2012. Fans clipped the short singalong because it sums up their bond in a few seconds. Online it circulates among pony fandom edits, nostalgia posts and soundboards as an instantly recognisable symbol of their early friendship.