Okay, so a long time ago, in the year 1899, there was a law made called "The Seats for Shop Assistants Act". This law was created to help people who work in stores, like the people who help you find the things you need when you go shopping.
The law said that if a shop assistant wanted to sit down while they worked, the store owner had to provide them with a stool or a chair to sit on. This was done because sometimes shop assistants had to stand for a long time and their legs would get tired or even hurt. Sitting down for a bit could help them feel better.
So, basically, the Seats for Shop Assistants Act was made to help make sure that shop assistants had a comfortable place to sit if they needed it while they worked in the store.