Some items' images cannot be modified

I am new to using Tynker with Minecraft. We were able to modify a block of coal by drawing a face on it, and the block of coal on our server then had the face. Success! We were also able to modify our own character’s skin, upload it to minecraft.net profile, and our character in the Java server had the skin. However, when we modified a golden apple and a snowman as we did the block of coal, the golden apple and snowman in the Java server did not respond accordingly. (The snowman has to be created by applying shears to a snow golem.) Can you think of any gotchas that could be causing this? The little green target / dot icon does appear on our modded snowman and apple images on Tynker, indicating that they should be activated.

We’ll check it out. It may be the case that we do not yet support some of the newest items, mobs and mods.