That looks very unprofessional. Imagine when you go somewhere and they ask you to scan the paper that's attached on the window with adhesive tape. Cmon, I wouldn't enter that store again.
Well, OP may be tight on budget, probably a small business owner not always going to invest much on something expensive to get started. For local business, bitcoin payment is not the primary option of payment.
Just
a small, well designed cardboard with a QR code on it for scan and pay can make the job done. It will look good and professional on the cash counter table.
If the address is the same for everyone, then you may analyze that when you send money from your address to store's address, it will be publicly available on blockchain and your address + the amount of money will be visible for everyone. It's the most privacy unfriendly step that someone can make. And if the card payment sounds more privacy friendly than this type of crypto payment, then why will someone bother and pay crypto? If a person is a crypto enthusiast, sure he values his privacy and won't pay with crypto in this case.
