Sooo... Twilight realizes that she's late with her friendship lesson, even though everypony and Spike thinks that there's no deadline. As she looks outside, the Sun starts behaving like a ticking clock, further putting the screws to Twilight.
After Twilight is driven crazy all day, the "time limit" runs out, and Celestia appears with a booming, angry voice, demanding a private audience with Twilight.
Twilight is scared into begging forgiveness. Celestia says it's no big deal. (So why the fire and brimstone?)
The mane cast was also scared by Celestia's booming, angry appearance into thinking that Twilight's absurd fears were actually real, and they also beg forgiveness in order to save Twilight from Celestia's wrath. Celestia, having already said to Twilight that it was nothing, turns their false-but-justified assumption against them and pretends again to have been angered, and puts the screws to the mane cast in order to teach them a false lesson about listening to crazies, and scares them into thinking that they're now also required to make similar reports on an irregular schedule... or else. Or else what? Exactly.
Twilight asks Celestia why she even came to Ponyville, if there was no deadline or punishment. Celestia says that Spike called for help because Twilight was freaking out.
So... was Celestia aware of Twilight's actions through the entire episode, using the Sun to tease her all day, and exploiting the truth of Spike's letter to avoid telling the real truth, or does she merely like to jump out of the shadows and yell "Boo!" when her friends are freaking out and scared of her?
Edit: Ditzy Doo wasn't even officially Derpy's name, it was under consideration as a possible name, among a few others, until the fandom near-unanimously put "Derpy Hooves" forward, at which point the official channels did more than add Derpy to the list of consideration, they chose it as the official name.
