After a hard day, relaxing in the fresh air is very pleasant, and useful, moreover. Probably the owners proceeded from such considerations, organizing this cozy corner.
A welded metal frame, the flooring can be wooden, plywood, from hardboard - it does not really matter. Awning for a tent here is an ordinary fabric. He will protect from the sun and insects, but so that the tent can survive the bad weather, it is better to do something waterproof.
In general, the construction is nice, it’s convenient to relax here. The downside may be the dampness that the fabric inevitably absorbs. But perhaps it’s planned to disassemble the tent for the night, bring things into the house, and rest only in warm, dry weather.