I used the same settings for the Dyntopo (7px) relative detail however im not sure why it looks like this compared to yours
Would sticking to constant detail lead to a better result for this in particular?
Omar is right, don't be afraid to experiment SSachuration. Over the years I've found that relative detail size can seem to behave slightly differently as Blender develops. Years ago 10px used to be my standard starting value. Then I started noticing 7 feeling like 10 used to feel.
So if you're finding that 5 on your screen feels like 7 in the video, it's more than fine to go with your 5.