Hi @Cloud, can you explain a little more about what you are trying to do?
You can drape a simple color (as in your screenshot) using Classification.
Draping an arbitrary image is harder, and not currently supported. See Drape imagery over 3D Tiles · Issue #7591 · CesiumGS/cesium · GitHub
I have implemented the capability to overlay WMS or TMS map services onto the terrain, but there is no example available for overlaying map services onto 3D tiles.