The bottom-center player on desktop is very short and unobtrusive. The same player on mobile looks awesome. But it takes up a large portion of the screen. If there was a way to start with a minimal (short) player and a maximize button to show the full player, I think we would be able to free up a lot of real estate for the visitor to see what else may be on the page.
In my example, I have a button being hidden by the size of the player. Personally I think the bottom-center layout is the best but the player on mobile is very tall and takes up much real estate.