It's based on C3 Technologies' product, which was unfortunately acquired by Apple, so don't count on Nokia's contract being extended. It uses a custom aerial camera system and photogrammetry toolchain to create 3D data with minimal human intervention.

Australian company Nearmap started with exactly the same goals and have a similar product (custom aerial photography system with automated processing), but they don't seem to have figured the 3D photogrammetry part out yet.