The fake-wood texturing on the concrete adds character, I suppose. It gets incredibly hot inside from the sun shining on it all day long.
The "Pack it in/pack it out" sign might come as a surprise to folks who aren't used to wilderness parks. There simply aren't garbage-collection services everywhere in the world.
It's not a lot of fun to carry one's garbage around while backpacking or bikepacking or horsepacking, but it's better than throwing it on the ground and hoping it blows away or dissolves. It also makes you very conscious of how much garbage you make.