Dumb question, but cannot find the answer

DW and I are getting a Big Country and do not remember seeing the round disc in the shower under the faucets.

I cannot find anything on this, but was wondering if this an access hole to the washer pipes behind the shower. Is this correct?

Also, any feedback on the Big Country when we go to pick it up next week? I have seen a few post about leaks.

Thanks
Chris