This episode is considered non-canon and the events featured do not relate to the series and therefore may not have actually happened/existed
"The Longest Daycare" is a 2012 Academy Award-nominated short film starring Maggie. It was announced at the end of "Lisa Goes Gaga" and the promo was included with the iTunes release of that episode.
The announcement featured a picture of Maggie's head overlaid on a moving sunburst pattern with a narrator saying, “I'm speaking fast because I'm so excited! See Maggie Simpson in her first starring role in 'The Longest Daycare' in 3D before Ice Age: Continental Drift, only in theaters. We've already done the hardest part: making the poster!”
Ice Age: Continental Drift opened in theaters on Friday, July 13th, 2012. "The Longest Daycare" is a silent film with only a musical score accompanying it.
As Marge drives Maggie to the Ayn Rand School for Tots, Maggie notices a butterfly outside the car window. Before she can react, they arrive and Marge drops her off for the day. After an intelligence and health screening which also involved passing through a metal detector, Maggie is taken past the "gifted area", complete with orchestra, to the area for "everyone else", based on her average intelligence.
Maggie attempts to make friends and join in on the activities, but all the craft materials are quickly taken or eaten. A butterfly floats through the room, but Gerald Samson squashes it against the wall with a mallet, then draws a box around it in crayon as his art. A second butterfly meets the same fate.
Horrified, Maggie walks away and discovers a caterpillar in another room and picks it up. A pop-up book shows her the life cycle from caterpillar to butterfly. When Gerald reappears, the caterpillar is on her forehead and she uses it to mimic him and his unibrow. Shortly thereafter, it enters the chrysalis stage.
Gerald then chases Maggie through the daycare, intent on adding the soon-to-appear butterfly to his collection. Maggie spots an open window and tries to release the butterfly, which has now emerged, but Gerald makes the blinds drop, squashing it. She falls to her knees in silent anguish as the orchestra plays nearby.
Marge returns to collect Maggie and the two drive away. Gerald raises the blinds to examine his prey and discovers that it is Maggie's bow, and the blinds fall back down on his head. As Maggie and her mom continue back home, the butterfly unfolds its wings and flies away from where it was resting on her hair.