Here you can collect all items from your last account. as you progress in the game. When a progress bar reaches 100%. it means you reached a milestone and you collect items to improve your account. Beware: after each progress bar reaches 100% you only have 2 hour to redeem that milestone !
The new rebirth system is based on milestones.
Milestones are represented by certain items from your dead account, which you can redeem/collect.