Unable to answer "What’s the surface here?" – Rue de la Carreyou (Path) – https://osm.org/way/905591344 via StreetComplete_ee 61.1:

ce tronçon de rue est en fait un mur.
on ne peu pas passer

Attached photo(s):
https://streetcomplete.app/p/332811.jpg
https://streetcomplete.app/p/332812.jpg