From Generator Rex S2:E12. It’s available on NetFlix, cartoonnetwork.com, and probably a bunch of other commercial streaming services. Only one volume of the series was ever released on DVD. There was a previous ul, but the image quality was bad and it didn’t set up the punchline as a brick. There’s one frame after it with sparkles surrounding the two, but the timing of it doesn’t translate well into a multi-panel comic; I could have shooped the sparkles into the same frame as the last one but it’s supposed to be coupled with the eye closure for animation contrast; I picked the frame with the pony’s eyes open because of the rainbow reflection in the conjunctival layer–it gets the point across more quickly than if they’d reversed the sparkles and the rainbow eye. I know it’s just a generic cutesy pony, but knowing the herd, there’s gotta be an OC or bg pony out there with the same color scheme. Maybe think about adding tags–the four above (at the time of writing this description) were all of the ones I could think of.
 
Charlotte Fullerton wrote an episode for S1 of Generator Rex. Most of the voice cast for the show is the usual suspects of bay-area VAs, so no voice crossovers afaik.