Cashiers generally have a chair, but during rush hour it's better to stand and work than to sit and work.
Also they are just trying to make your easier by packing the stuff for you, if you don't want them to, you can just tell them and then they will leave you be.
Also they are just trying to make your easier by packing the stuff for you, if you don't want them to, you can just tell them and then they will leave you be.