Desert golem
better golems and cactuses I guess. biome dependent mobs are a thing though, not just golems but a bunch of stuff.
overall vibe
fairly subtle but you will notice differences in the grass block, stone bricks, wood, mushrooms and flowers.
Ore tweaks and connected textures
Connected textures make Ores blend seamlessly with the environment.
mobs and models
many models and mobs are changed, 3D rails, varied azalea bushes, better minecart textures, better skeletons and mobs
gui stuff.
the whole gui has been overhauled to be more immersive
RED sand
Red sand is redder. Red sandstone is chunkier. Also, plant life in the mesa and a few other biomes will have custom textures.
biome specific variations
some blocks just need better textures in specific biomes.
Custom Books and Potions
Custom books and potions for 1.21.5+ also peep the custom inventory for chest minecarts
connected textures
the pack supports connected glass and some overlays. diorite is less heinous to look at. nothing that will disrupt building. (also peep the color tweaks on the chests.)
armor models
cleaner and cooler armor