The street level imagery on ja.is is from summer 2022. In an announcement from Kópavogsbær March 2024 speed limits were reduced on almost all streets in Kópavogur. https://www.kopavogur.is/is/frettir-tilkynningar/breytingar-a-hamarkshrada
I've personally not surveyed whether they've updated the signage in Digranes but in Fífuhvammur and Vatnsendi these changes have already taken effect on a street level (on a legal level these changes have already taken effect, see https://www.stjornartidindi.is/Advert.aspx?RecordID=85a3c6b0-255c-40de-9288-8c46f8d7b870).