Every number is Russ’s own rating out of 10. Russ has previously stated that he never scores in sponsored videos, so the food he reviews carries no applied pressure or bias.
Second bottle tasted. It is likely the one he calls sweeter, tasting like a normal but more indulgent chocolate milk. The 9/10 is inferred from '10 and really a 9' and has no on-screen graphic, so the attribution is somewhat uncertain.
What it’s like
Flavour: That one's sweeter
Tastes like: taste like a normal chocolate milk, but a bit more indulgent