Sometimes I find sorting things relaxing... not three days of sorting, though. I really need to summon Twilight to sort all my comic books -- there's no other way they're ever going to get in some sort of shape where I could ever find the ones I want to read again.
Her attempt at science was kind of amusing, even if Discord hijacked it to make fun of her. Maybe that's the moral of the story -- you can't recreate spontaneous humor. Except that, you know. You can. Or, well, there are people who can. Pinkie should have been able to do it. Still, their experiment was not the way.
Rainbow and Discord mimicking each other.
The horrible awkwardness of the science brunch.
Zecora's decorative cauldron.
Pinkie Pie drinking the Kool-Aid. Applejack ruined the scene slightly afterwards though.
And it was neat how they turned it all around on Discord at the end. And then Twilight offered him an orange as a peace offering. Heehee.
Overall, it was a pretty good episode, but there were some annoyingly preachy bits and they really milked all the things. Even if that was part of the joke it was still annoying. 2/3.