Even if you could you would probably not be able to change the walls and IMO they give you great privacy. As for the walls there are lots of great outdoor art pieces bigger is better and most are canvas or very light wieight metal and no issue with weight for hanging. IMO plants make an outdoor space a lot nicer and why not have them during the growing season to go along with the outdoor furniture you plan to get. I also think you will need some lighting just not string lights 2 ideas for wall art and if you google outdoor wall art there are 100s of ideas
Q
First picture is amazing
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