One of the easiest ways to embed images or spritesheets into your PicoSystem projects is to convert them into arrays of data that can be pasted directly into the code.
This tool allows you to drag and drop an image onto the page which is then converted into the PicoSystem graphics format (16-bits per pixel, 4-bits per channel) and output as either C++ or Python code to embed.
Remember PicoSystem only has a small amount of RAM! You want to make your images as small as possible - probably no larger than 128 x 128 pixels (which is around 32KB).
The embeddable code will appear here.