Is this just a graphical representation of the actual outcome of the bets or are their luck involved with the bounce of the ball? >
it is just the graphical representation of the actual outcome of the bets
you can see it when you start auto drop and tab out
when you return to the tab, almost all of the balls will drop simultaneously
the game is provably fair i.e. for every ball there is a result of the server seed+players seed+nonce combination that determines the result of every particular game
each and every ball is that separate game and first the result is calculated and then the visual representation is coded according to some predetermined paths
I think every result has 10-50 different graphical representations, sometimes when you are playing plinko long enough you recognize certain "troll balls"
when a ball jumps all the way to the centre from a surefire 1000x slot you were so hoping for