The Cuttlestone target is derived from the Cuttlefish Android build (cf_x86_phone). It is a virtual Android device, hosted in a VM which runs on the Google Compute Engine. The normal workflow for building and running Cuttlestone is:
source build/envsetup.sh lunch cuttlestone_x86_phone-userdebug make -j dist
Key build artifacts:
out/dist/cuttlestone_x86_phone-img-eng.android-build.zip - *.img files for the cuttlestone_x86_phone target (boot, cache, system, userdata, and vendor images)