A Chromium bug post titled “Multi-Profiles: Add support for custom avatars”” was created in 2011 and is the fourth most starred and open issue on the Chromium Bugs site. Chrome currently allows you to associate an avatar to a profile from a list of bundled images or your Google Account avatar if you are logged in to Google. Chrome will display these avatars in the Windows taskbar icon so that you can differentiate the browser sessions. An accountant uses different profiles for each client so that they don’t get mixed up with other clients.”
Source: https://www.bleepingcomputer.com/news/google/chrome-may-soon-allow-custom-avatars-for-browser-profiles/