I think the video initially tries to re-create a feeling of starkness (working by lamplight late at night), but ultimately belies the true starkness of the song with The Darn Vest and Paul's bad emoting.
I think this has often been Paul's ongoing image problem: He is usually in actuality just as "deep" and creative as John, but presents himself in a more trivial, lackadaisical way, which reviewers/the general public pick up on. As a result, he doesn't get the critical acclaim that John gets.
When I was younger and first discovering The Beatles, I adored John and "John [as opposed to "Paul"] Songs." As I got older, I started to recognize more and more that Lennon was a bit of a poseur. His persona influenced how his songs, and how he as an artist, were perceived. If he said something serious, he was sure to point out how serious he was being. McCartney, on the other hand, wrote sad and serious and superficial and day-to-day and bombastic, without making any pronouncements about how we, the listeners, were supposed to receive.
This song, "Waterfalls," is from the "McCartney II" album, 1980 (pre-John's death). The whole album is electronic, stark, and experimental for McCartney; he played all instruments, did everything himself.
DON'T GO JUMPING WATERFALLS
PLEASE KEEP TO THE LAKE
PEOPLE WHO JUMP WATERFALLS
SOMETIMES CAN MAKE MISTAKES