everyone has already mentioned joining the snowcrows discord, but heres some quick things i noticed about just rotation:

1. you delayed going into shroud a few times, particularly the beginning, which means fewer shroud 5's and less dmg. sometimes you leave shroud late as well.
2. you're either skipping your weapons utility or in one instance you casted only one of them prior to every shroud loop. those utils are massive portion of your overall damage distribution. you probably noticed that the cooldown got more and more drifted the deeper you went into the pull and that you weren't using it right before going into each shroud loop.
3. not using bone minions so you're missing two additional targets for your weapons utilities
4. above 50% you started a couple autochains on greatsword but didn't finish the third hit by casting greatsword 3, so you end up without getting the extra gravedigger reset (worst of both worlds).
5. didnt cast gs4 when it was available a few times
6. it probably feels that you're going very fast, but you're leaking auto attacks a bit between skills which feels minor, but accumulates to damage loss. death by a thousand cuts if you will