I could not add a second picture to my original post so here is that same screenshot zoomed in & the items in question circled.
As stated in the original post, my first thought was it was artifacting.. but it looks too uniform to be one.
If you are able to zoom in on the original post in this spot it may be a little easier to see, or if you can find this precise frame in the video you may be able to get better quality overall.
Original post:
https://www.reddit.com/r/CODZombies/s/SS21uNMKi2