Unable to answer "What’s the surface here?" – Foot Path – https://osm.org/way/377424702 via StreetComplete_ee 57.4:

The map is slightly inaccurate because there's no direct connection between the pavement and the adjacent street. The material itself looks like tarmac that continues over into concrete tiles.

Attached photo(s):
https://westnordost.de/p/215681.jpg
https://westnordost.de/p/215682.jpg