Describe the bug
Whilst the bucket item is a 16x16 sprite, the biofuel and oil textures rendered inside of them are 32x32. This is a texturing "don't" known as 'mixels', and it makes these two buckets look strange.
Furthermore, the fluid textures are animated to appear to be flowing downward inside of their buckets, which does not make sense.

Steps to Reproduce
Steps to reproduce the behavior:

• Create a new world in Creative mode.
• Obtain either the Biofuel item or the Oil item. Observe the item texture.

Screenshots
Note that the fluids are higher resolution than the buckets. The animation can't be shown in a humble screenshot.

Environment (please complete the following information with the version):

• Minecraft: 1.16
• Mod Loader: Fabric

Eh, people don't excessively look at bucket on frames and the flowing down due to the rotation of the png, I'll fix this but as for the pixel size, it's fine.