XP orbs iare prettier, twinkling between light blue, yellow and pink. they are also more star shaped and less round.
XP bar is rainbow coloured.
Food item in GUI are pumpkins not meat sticks.
xp level text is yellow.
Enchant glint is more subtle than vanilla and rotates through colours.
Trident tips are emmissive.
Tridents held in the left hand (offhand) renders as if being worn strapped to the back in third person view.
Endportal has dragon siloettes instead of dots flying across it.
Endsky is plain with stars rather than static.
Enderdragon has emissive purple spine spikes and wing edge.

some features REQUIRES OPTIFINE