These icons present the block's main texture as a simple square, making it easy to identify colors and patterns at a glance.
Using a limited color palette and low-resolution (e.g., 16x16 or 32x32) pixels can give the inventory a retro or "Minecraft" aesthetic. Inventory Interface (GUI) Layouts
You can design the inventory window with specific textures, such as wood, stone, or metallic frames, to match your game's world.
GUI 2D Blocks in inventory - Minecraft Resource Packs - CurseForge CurseForge