I, personally, thought the joke here would be referring to this.I
 

 
@Durabiznik  
What race are you? What’s your skin color? Which nation do you swear your allegiance to?

@Lord Of Dorkness  
I don’t see how an irl furry dog person would completely invalidate towels. For one, people wear dumb shit for style all the time, for two, some might find it kinky, and for three, it still dries you. It gets the water off the fur. Maybe you could shake it off like a dog, but that won’t work quite as well, and still, why make a wet mess out of the room?
 
The wall drier thing also sounds interesting but also I don’t think would be any more reasonable for dog people than it is for human people.

@neo4812  

 
Read a furry story once that dealt with this. Can’t recall the name, but the premise was that a lot of people transformed into animal hybrids for some reason. Virus or something?
 
Anyway, pretty standard wish-fulfillment and nothing special, to be blunt, but the author did some interesting world-building with how some of the slice-of-life stuff would be effected. One of the few parts that stuck with me being that the towel was all but obsolete for those effected, and instead there were these heated wall fans. Like a giant vertical hair-blower you mount permanently to the wall, like a towel rack, so you could just step out of the shower and blow yourself dry.
 
The rest of the story was rather meh, but I thought that was a neat idea for how to deal with wet fur as an intelligent species, and it’s stuck with me.

Everyone is talking about real body care, specifically for the human body, but honestly I see this joke more as implying ponies have thicker manes/tail hair than people do and that means they make more of a mess than most people if their hair is wet. Spike’s probably irritated with Twilight for being a semi-nudist who just walks around the castle dripping water everywhere that he has to clean up.

@Neko Majin C  
If I don’t wash my hair every 24 hours it starts to clump together and gets really oily and gross.

@Neko Majin C  
What?

Your hair really only needs to be washed twice a week. Any more and you risk damaging your hair leading to split ends and early hair loss.

@TheSneek  
that’s why the hair dryer was invented, only 10 bucks at Walmart even less if you buy from a 2 hand shop or a garage sale

@TheSneek  
just plan it away from me, i don’t need to smell your head sweat.

@Durabiznik
 
Washing both your body and your hair takes longer than just washing your body, plus you then have to spend time drying it.
 
This is especially important if you have a full day scheduled.

@FinalDraft  

 
Well, Starlight probably likes it if her hair smells like a sweaty old mat, what with her being a filthy communist and everything. Props for Twilight for not being an uncivilized animal.

In media, shower caps are visual shorthand to indicate that someone is going to shower or has just done so without actually showing them in the shower. IRL, they’re used to preserve hairdos, and because some types of hair can be damaged by constant washing, especially if you can’t afford fancy shampoo. There are also other uses for them in salons and spas.

Magic.

@Durabiznik  
I know, right!? Then again, though… I have short hair, so mine dries in less than 20 minutes… so… I guess I don’t know. Shrug.

Love the cup.  
Twilight is everything but a princess, hah.

Actually it only takes seconds, thanks to the power of RAGE.
 

The hell is even the point of showering if you don’t wash your hair?

Lol

never understood the mere existence of showercaps, why wouldn’t you want to wash your hair while in the shower? just either let it air dry or use a hair dryer

#1 ASS IS

@CountColtnackh  
Or celestia

Twilight’s mug though…

@Backgroundpony  
At least she’s higher than Flurry Heart

love the cup

Tail drying problem solved.