To view the categories of other people's Douyin stores, follow these steps:

Open the Douyin application and log in to your account.

Find the homepage of the Douyin user you want to view. You can do this by searching for their username or following them directly in Douyin.

Once you are on the user's homepage, scroll down until you see the products they have posted.

Click on the product and enter the product page, where you can see the product's details and price, among other information.

On the product page, swipe down until you see the "Category" label. Click on that label to see the category to which the product belongs.

You can also click on the user's store link to enter the store homepage, view all of their products, and see which category each product belongs to.

Note: Some Douyin users may not have created a store, so you cannot view their product categories. In addition, since the opening of a Douyin store requires certain conditions to be met, not all users can create a store.