For a comprehensive list of other examples of issues with 2D planes in models not being mirrored as expected, click here.
The bug
The planes composing powder snow do not mirror on the back as one would expect, resulting in physical/illogical weirdness.
Fixed model (Mojang has full permission to use this fix):
[media]
How to reproduce
Place a powder snow block
View the cross on the texture as shown in the screenshots
View the exact same section of that texture plane on the direct opposite side
Note that the exact texture pattern at that position is different, even though it should be the same
Linked issues
relates to 18
MC-190774
Stonecutter saw spins both ways simultaneously
Resolved
MC-199237
Back of ladder is incorrectly mirrored
Resolved
MC-199239
Vines appear incorrectly mirrored when viewed from behind
Resolved
MC-199241
Texture planes of cross models appear incorrectly mirrored from behind
Resolved
MC-199242
Texture planes of crop models appear incorrectly mirrored from behind
Resolved
13 more links
I can confirm.