See mockup: https://s.codepen.io/enalean/debug/615728ad14def79e9b694647c582ce16
Functional overview
The avatar corresponds to the Assigned To / Contributor semantic of the card. The avatar has a "title" attribute to show the Display name. Avatars are shown for all types of cards: Top cards or children cards.
Progress, Initial Effort and Remaining effort are only shown for Top element cards (Parents) for example User stories, not Tasks (Children).
Progress on card has the same look as Scrum Planning: it is a border on the bottom of the card with the Tracker color (like the border on the left).
Initial effort is shown as a badge on the top-right of the card.
Remaining effort is shown as a badge with an arrow, below the card.
Initial effort and Remaining effort have a popover to explain them (when you hover, it shows "Initial effort")