#file_contents can be used to add the contents of a file (text or binary) into the data section of the outputted WebAssembly binary, and gives you access to it as a [] u8.

You can use this to embed anything in the binary that you would have had to put in a string literal, or load at runtime.

image_data := #file_contents "image/path/here.png";
pixels     := convert_image_to_pixels(image_data);

This way, there is file I/O to load an image from disk. It is already in the binary ready to be used.