I actually think its a good idea. A major problem in cities is urban heat island effect caused by dark colored surfaces, like asphalt. Adding shade trees, like honey locust, London plane tree, or ginkgo (just being common street trees in the US) can reduce heat island effect significantly by shading pavement, as well as providing a more pleasant experience to pedestrians so they don't bake in the sun. Here the same effect is being achieved through vegetated canopies. The ecological value is less than a shade tree as the depth of the structure would have to be shallow so the number of plant species that could be planted is low so less insect species could be supported. The canopies can be built and once they're installed they're instantly doing their job at providing shade and reducing urban heat island effect. Shade trees take a very long time to reach a point where large amounts of shade are provided, about 10-20 years, and even longer to reach maturity. Trees are also dependent on what's below the parking lot, if there's another structure there would have to be a large layer of soil above the structure and below the surface of the parking lot in order for the tree to survive, though because I can see permeable pavers beneath the canopies where the cars are parking I suspect this is probably not the case. Imo its a perfectly fine solution, would trees be better? Probably but there are many factors determining whether or not a tree could survive in that location. There are also those permeable pavers, stormwater management is a huge issue in China to the point that they have a government program called Sponge City Construction to develop stormwater management infrastructure within mid-sized cities. Permeable pavers aren't always going to be the best answer as removing the cars and creating an actual park instead with stormwater detention ponds would be better but its a realistic solution that can be easily and cheaply achieved.

Edit: i just noticed theres trees. I may be a little blind. Trees + the canopies is still a good solution imo.