If you live somewhere that you have good weather year around so they can always get outside you should be able to keep two hens in that. Three might work but it could be a little tight.
I would also pass. Looks cool but not practical as wind/rain would just blow in through those sides. Plus I'm imagining myself having to crawl in to clean it, and that's 100% nope.
A small wooden shed, tall enough to walk into. Consider a prebuilt one. You'll need to cut in some ventilation and add roosts and nests (you can buy premade nests or use very simple ideas such as milk crates, kitty litter buckets) but that will minimize the work you need to put in as much as possible, while still providing a very safe home for the chickens.