When you create an account with Zoom you are put into a company folder with everyone else in your organisation with the same email domain. If you are using a well-known webmail client such as Gmail, Hotmail, Yahoo etc. an exception is made and you are not entered into a company folder.
However, many people have email addresses with smaller webmail clients that Zoom hasn’t identified. Therefore, anyone who uses that webmail is entered into a folder together. From this, you can see anyone else in the same folder’s email address, username and profile picture. This is a serious privacy issue and it is still unclear how Zoom plans to fix this.
You can read more about this here.