Invi's Impulsive Inspection is a comedy in the guise of a review series, and at the current moment appears to be plot-driven.
As the "Impulsive" in the title implies, there is no real reasoning as to why one set is chosen to be featured. It tends to be something that is currently on the shelves but is not restricted to a current set, or even a set.
The first arc of the series, comprising of the first two episodes revolve around Invi having the script to his show sabotaged supposedly by deadmatoro's college roommate. A conclusion is never seen on screen.
The series caused some controversy in the second episode when people were outraged the Invi placed the pieces of his BrickHeadz Thanos directly on beach sand.