If Putin wanted to inflict as much harm on Ukraine as possible... we wouldn't have Ukrainians casually walking up to Russian soldiers and offering them a piece of their mind, or offering them a ride back to Russia.
Kyiv would be under heavy bombardment and no one would be casually driving around sharing the road with Russian armor.
None of this is in line with the narrative of "full invasion, occupation of Ukraine". This is like a much more focused action of a more direct and limited objective.
they're going to bloody Ukraine's nose
embarrass the west, especially NATO and the US administration.
secure the Donbas region and obtain recognition of their independence.
then go home, having signaled their resolve to any pro-Russian faction or neighboring region thinking of joining NATO.
http://www.youtube.com/watch?v=oFH9wb5RrAc
If they end up with all of Ukraine, that would be by accident and the incompetency of the West and Ukraine.