Floor outlet?

Floor outlet

A floor outlet is great, but I'm not sure that it would be an easy thing to add. You can put an area rug under the desk and run a discreet extension cord under that. (You may have to cut a slit in the rug, if possible, to bring it up under the desk.)

Or you can "chain" some furniture together to hide a cord. In my living room, I have an extension cord (same color as the carpet) that runs from the wall, under a bench, then under a chair, then up to a lamp on a table between two chairs. The cord isn't visible from most of the room, even though it's uncovered for a foot or so. In an office, maybe a side table or chair, or a credenza could help hide it. If it's on the far side of the desk, away from the door, it will be less visible than you think.

I love your room. Have you considered an Apple Laptop....you can use wireless printers and they are great! I had a desk top for over 7 years and my nephew finally talked us into a laptop...Would never go back. No wires!
Good luck.