In a Wendy's commercial from the '80s, a Soviet fashion show is shown as the same grey dress for all occasions. What was the fashion industry really like in the USSR?

The fashion one would likely see in the Soviet Union varies somewhat on what specific era that is being referred to. I'll try to get through all of them, but there's really a lot more to it and it's surprisingly interesting.

##Pre-Stalin

During the 1920s, there was still some remnants of fashion in advertisements and magazines. Still, there were many, especially the Bolsheviks who opposed fashion and associated it with Capitalism and the bourgeoisie. It also had the connotation of sexism since it promoted gender roles for women. Some considered this inappropriate in a movement designed to bring equality. There were some magazines that promoted working-based attire for women that was more gender neutral and practical.

##Stalin

Now, when we get to Stalin's reign, fashion began to be less about function and more about beauty and orginality. They were more extravagant and aesthetic than the 1920s forms. These fashions still tried to distance themselves from Western fashion. More peasant-looking clothing was discouraged since it encouraged the notion that Communism had to be dull and plain. Most of the more ornate outfits were outside of the average woman's ability to obtain. Therefore, some magazines promoted Soviet women to make their own clothing using things they can easily obtain. This was around 1930s-1940s.

##Khrushchev

The Khrushchev era saw fashion go back down to being a little more modest. The state looked at Western fashion and promoted those that fit the mold of being more moderate, modest, and traditional fashion. This was because Stalin's era had triggered contempt from the Soviet populace since there were many fashions being promoted that the average person simply did not have access to. This is where the Wendy's commercial likely got the idea of Soviet fashion being plain and unoriginal.

Interestingly enough, among the youth a counterculture arose that was based on shallow impressions on Western fashion. Most of the ideas for this fashion came from Western movies that were shown in the Soviet Union. These were usually sunglasses, short skirts, American hairstyles, etc.

I may continue this later if more people are interested, there's still a lot more and this post is already pretty long.