the TVs on the shelves at my local Walmart are attached to each other with wired alarms. Just how are you supposed to buy a TV if you can’t get it off the shelf?
They have boxes in the back. All of those on the stands are for display only.
Sometimes, you have to take a slip of paper with a UPC on it to the register, and they bring it out from the back for certain items (usually oversized things like furniture, etc.).