Here's a photo of my "wall hung china closet" (toilet) that must be replaced with a new toilet.

It's bolted to the wall so when it's removed, the plaster might need a little work because the new toilet tank will be much smaller and so the wall behind it will be more visible. Here's the issue: The plumber will come over and remove the toilet and have the new toilet standing by. I want something decorative done to the wall behind it that can be put onto the wall immediately so that the plumber doesn't have to wait to install the new toilet and so I don't have to wait more than one day without that toilet. I was thinking of using (1) pre-made wainscoting of some kind that can be immediately applied to the wall, (2) cover the wall with wallpaper so that the wall doesn't need much preparation for it , (3) cover that one wall with a small mosaic tile. Can anyone tell me which of these options would be the fastest. If you have other suggestions, I'd love to hear from you. Thanks.