First: the metal vent to the right is a direct vent for a heating system. Since this picture was taken in Melrose, Massachusetts, there is a problem with this direct vent. Do you know what the problem is?
Yes, it is low enough to get covered with snow. Blocked vents are bad. They can lead to carbon monoxide in the house. But, modern systems have a safety that shuts it down, automatically, if the vent is blocked with snow.
Second, what is that little metal house-looking thing to the left?
It’s a chimney cap. It belongs at the top of the chimney, not on the ground where it is doing nothing of service.