Honey and yogurt are common additions to bread doughs and for good reasons: each imparts distinctive (and subtle) flavor and also helps to keep the bread moister for longer (meaning it will keep longer after baking). In this recipe, they do just that, plus the loaf is brushed with milk and then sprinkled with poppy seeds. By the way, besides helping the seeds adhere, the milk promotes browning of the crust during baking.