Why are the snow layers inside the fence?
Idk if this is supposed to be this way, but the snow layer is somehow inside the fence.
When I middle-click I do not get the snow layer, I get the grass block, It doesn't have a hitbox and disappears when I take the fence away.
As the fence and the snow are separate blocks I don't think they can be inside each other like that. I know glow lichen and vines can do it, but those are just Blockstates.
It is possible that this is intentional, but I just found it weird.
I think it's just an Optifine feature... It's based on surrounding blocks. If you take away all adjacent snow, it should go away... you can also turn it off. Options > Video Settings... > Quality... > Better Snow: ON to Better Snow: OFF