How can I add a web mercator image?

I add the same image both in leaflet and Cesium. In leaflet, the image works fine; but in Cesium, the image looks like have some position offset in lat. Here is the demo link:https://codepen.io/qjvic/pen/WNwMGYr
In github,https://github.com/CesiumGS/cesium/issues/9142 metioned this is caused by projection. Can I add the web mercarto image correctly in Cesium without any additional operation but just modify my js code?