From what it looks like, the medal system is nothing more than a way of keeping players active and a way of awarding active players XP.

I have seen nothing about actually displaying these medals or anything about the purpose of the medals beyond an xp reward system.

The ticks displayed are most likely a way of notifying the player that they have indeed completed the requirements for the medal in question.

If I see anything I'll update my answer and keep you posted.

I hope this answers your question