Hi, I succesfully installed pm on my nexus 5 device. But I could not ssh to the phone as suggested in the tips (ssh phablet@10.15.19.82). Any clues on why? Where does the IP come from?

Apparently NetworkManager does not use dhcp automatically for USB networking (might be security related). You can either set up a new connection for usb in the NetworkManager gui or call 'dhclient usb0'