To make best use of this video, try to play exactly in time with the clicks, in the pocket. This helps make sure you aren't "cheating" by playing a simpler rhythm, as is so easy to do involuntarily with polyrhythms.
It might help to play one hand at a time first, and try playing ahead, behind, then exactly on the beat - you are in the pocket when your taps and the metronome clicks merge together completely. It's like you make a new sound together with the metronome.
This video plays a steady rhythm on the right hand - red - and the other hand (blue) gradually changes.
Each rhythm is played for two measures. The intermediate polyrhythms span 2 measures so the two hands don't always come together at the end of every measure.
All this helps with independence and flexibility when playing polyrhythms.