This would be epic if this works.
I see two ways to load textures:
load the Desmos canvas into a CanvasTexture. This would allow a maximum of one texture this way unless more Desmos windows are created.
Load images from the Desmos image capability. These are accessible as data URIs in the expressions list, and TextureLoader supports data URIs, so this is a perfect fit.
This would be epic if this works. I see two ways to load textures: