This looks to me like some serious 'corner cutting' and it looks tacky and un-professional.
First thing I think is "why is the vent so far offset from the range hood in the first place?
What's more disconcerting is that this is a highly visible, cosmetic detail.
They chose to use stock, low grade galvanized ducting elbows, and no flange to hide the imperfect edges of the hole cut into the ceiling.
I immediately start to wonder where they cut corners where it does really matter.