In an unprecidented move, AWS makes account names more useful. They're now displayed in the top navigation bar, I had to enable functional cookies to make this work. If you don't see it yet, from the footer click Cookie preferences and allow functional cookies then hard refresh.
The account name comes from the name given when you created the account, this can be updated under the Account settings.
Also I find it hilarious that they had to include that this was free in the announcement:
Read from linkThe account name display feature is available at no additional cost in all public AWS Regions.