Open up a "discussion" tab once a player completes/views the solution of a puzzle.

Might be copying chesstempo, but damn this will be a nice feature. Sometimes there are tactics that players don't really understand, it would be nice if players could comment/discuss the tactic. Else, some players might end up downvoting a good puzzle because they thought the solution was strange!

For example, look at puzzle #62599, a nice move to trap and win Black's knight. But it has been downvoted to 0 by people who probably thought it was just a faulty problem (after all, Bc2 looks like such a strange move!)

If you click on the game its from there is often discussion there.