I've never seen a meat counter employee re-zero the scale after putting a container or wrap on it. I do occasionally see them reading -0.1oz or something initially, presumably to avoid the need for the employees to zero it out each time they weigh something.
They simply adjust the tare weight in the scale and that's it. They do it anyway with their own 1-use plastic boxes or sheets.
I've never seen a meat counter employee re-zero the scale after putting a container or wrap on it. I do occasionally see them reading -0.1oz or something initially, presumably to avoid the need for the employees to zero it out each time they weigh something.
My feeling is that they have a few presets available for the containers they use, but it totally can be changed to a custom one.