Probably after having read their selection of newspapers similar to those I posted yesterday, these taxi drivers are enjoying a game of chess! I see them quite often in the same location, so they must be serious rivals. When a customer comes, they take their board into a nearby cafe for safe-keeping. Notice that one of them drives a Mercedes taxi, not uncommon here, no kidding, since originally one could important an expensive car much more cheaply if it was intended for "official" business.