While in execution a lot bothered me about this episode, the overall picture is quite fitting to show some differences of Equestria. I found it weird that toupets don't seem to be a thing there. It was a bit funny how they treat a mane like a very special and magical thing, but Pinkie Pie has shown long ago that there's something to it. Rarity just utilizes its magic in a somewhat different way, heh.
The bottle confusion was just one of those lazy things. At first I didn't even realize they had gotten two different liquids, because I assumed they'd at least get a label or such. The way it was set up one would assume Zecora did it intentionally.
And with all the different tries of toupets improvised out of anything but hair that gave a totally different look, it was odd that nopony suggested to her to use what's left of her mane for such.
P.S.: Role switch would have resulted in Punkie Pie. I'd have loved that just for the ... pun!