VHS tape has one "cog" blocked off - can't play it
So, I posted these images to Reddit under /r/whatisthisthing, and the answer that came back was obvious once it was offered:

Someone has taken a normal tape apart and re-assembled it with the take up spool upside-down.
It can't be a cleaning tape because it will not engage with the take up spool drive. A machine might just spit it back out but it could slam into the drive mechanism and cause some damage.

You will have to take the cartridge apart and carefully flip the spool over. No telling what other nonsense might be going on inside that cassette, however. So standard YMMV disclaimer applies.