If a mural or art piece is commissioned by the property owner, or created by them, that would be acceptable. There may be some murals that were not commissioned or created by the owner that may be acceptable, but they must be unique and distinct.
The Unique Art clarification has more info one what may or may not be eligible, and many of “art” Wayspots in Brazil seems to be vandalism. The 2 you gave as examples seem like they were spray painted on with stencils that may be easy to come by; the Team Valor one many have seen before, along with the other PoGo team logos, and it’s pretty easy to find those stencils for sale online or how-to guides to make them.