These are common in Turkey and generally used in both sides of a transaction. I saw them in Syria as well (10 years ago). There, it seemed that part of the purp

These are common in Turkey and generally used in both sides of a transaction. I saw them in Syria as well (10 years ago). There, it seemed that part of the purpose was to mitigate "accidental" physical contact between men and women. Several women I knew there complained about guys getting fresh (touching their fingers or hands) during transactions. The tray prevented this. In Turkey though, I think it is more for transparency in the transaction.