How do you take good plate photos with a phone in the venue?

The phone sits at the guest's height, by the window, with the whole plate and no flash. A filter does not fix a dark plate that should have been moved out from under the lamp. Clean the lens, turn the flash off, and pick the table that already has light before the plate comes out. The usual miss is a top-down frame with a thumb and a ticket at the edge, so the menu cannot tell what is there. If the phone is only a bridge, the file kept for the menu is still the one from the shoot, not that test.