Answer: For POS sales, it will show what user was logged into the POS on the Orders page in your admin under the “Shipping” column. If you export a search from the Orders page to csv, the shipping column will be on the report and display the admin user name for each order.
For example, this search shows that the “CrystalCommerce Support” user completed these POS orders in our testing admin:

Because of this, we recommend that whoever is using the POS is logged into their own account. If you have multiple employees using the same POS, you may want each one to log out after completing the sale, so that another employee isn’t using the POS under their name.