Rather, it's the ability to customize the Avatar for the account's profile picture. Everyone had anticipated that Roblox would eventually add something like this, or that the team would do ...

Roblox has been working hard on improving certain features for users and creators, including the UI! Details here.

The built-in character customization feature can optionally import data from your Roblox profile, allowing you to use items available on the Marketplace.

There are plenty of people right now within Roblox, and that means some special privacy settings need to be turned on.