The waiter has just made a very funny mistake. See, he thinks Twilight, Rainbow Dash and Rarity are all dating, when it's actually just Twilight and Dash. Rarity thinks it's very funny not to correct him. Now how far can she take the joke?
Sunset Shimmer really did not expect to wake up several years in past before she left through the mirror. Now she'll have to make due with her new reality, as well as two pestering princesses that won't leave her alone.
Minuette has an imaginary friend that lives in her mirror. Nopony ever talks about it, but she doesn't really hide it, either. The thing is, her imaginary friend is very real. And he's trapped.
Anyone who has sought counsel from Princess Celestia has met Raven, her most faithful aide. She has been a veritable second shadow to the princess for as long as the castle staff can remember... longer than they can remember, in fact. Much longer.
Trixie's line of work is dangerous. But she's a careful showpony, and that's why she's only died a few dozen times in her career. She thinks this is normal.