Upon starting the game or reloading resource packs, the message Texture minecraft:block/sniffer_egg_slightly_cracked with size 40x32 limits mip level from 4 to 3 is logged. I don't know if this actually limits the mipmap size (which would limit the size to 3 instead of the current 4) or it's just a logging error.
MC-261232
Texture minecraft:block/sniffer_egg_slightly_cracked with size 40x32 limits mip level from 4 to 3
Resolved
Fixed
3
It limits the actual mipmap; mipmaps work on power of 2: 1, 2, 4, 8
because of the 40x32 size, it's 20x16, 10x8, 5x4
non-scaled down mapping isn't included in the mipmap count.