Sassy’s like  

She must like challenging herself.

@AaronMk  
Keep in mind that Rarity has to manufacture everything herself, too, and her reaction to a looming deadline is “stay up late, panic, flip out, blame other ponies, and start eating ice cream”. Mass production is probably the best thing that could happen to her.

@M-DitzyDoo
 
The fashion world in general relies on mass-producing one fashion set for a season before moving on to trying to find or create the next best thing. Sassy Saddles really probably wasn’t far off from what is practiced by major, high-end designers like Calvin Klein or whatever.
 
What was really at fault was a lack of communication between the two. Sassy has the marketing experience to build a solid foundation but Rarity was not aware or ready to take hold of the major business world. At the start they weren’t ready to perform mass production of something which would have still left Rarity capable of producing individualized fashions.
 
The episode really feels like the conflict of corporate vs marketing with marketing just wanting to expand the brand as broadly as possible. Where as corporate has some poorly communicated philosophy that they discover to their shock the rest of management they hired and organized decides they don’t want to follow.
 
And then Rarity leaves a young still small business on its own with marrying herself to it for a decade.

@Philweasel  
Experienced in failed boutiques, mind you. Sassy was trying to sell what was in fashion at the cost of variety, where Rarity was making a variety of fashions. If we assume this is what Sassy always does then as soon as the trends changed she probably panics and the house of cards comes crashing down. She seems to be good at finding trendy things, but seems to forget things aren’t always going to be trendy. So while Sassy was drumming up business now, Rarity’s style would get more business long term.

Even Rarity kinda agreed, but the issue was Sassy didn’t ask her.
 
Even if Sassy is a more experienced businessmare (and her ideas were clearly making a lot of money), Rarity is still her boss.

“the rain in spain stays mainly in the plain” pretty sure that was the reference there

@Kerion  
Especially considering it was part of an entire line of “Princess Dresses”

oh, after reading the comments it seems Sassy wasn’t really being mean, but just trying to help Rarity succeed

Show writer vs. editorial staff in a nutshell.

Is anyone else thinking if she was a persona character she would be the emperor arcana?

@Grieffon  
Yeah, “stain” is not a good word to associate with clothing.

@Lawful Girly
 
Bahahahahaha XD

Support her on Tumblr!

@Grieffon  
Still better than the generic ‘Princess Dress’ name Sassy gave it.

She did get the joke; she just thought that many of the customers wouldn’t.

To be fair, “reign in stain” was a terrible name.

What was her original name? i kinda missed it.

To be honest, it wasn’t exactly the best name for a dress.

I know, that was terrible.