How can you fill a square drawn with a canvas without using DrawShape?

Here's yet another way to turn a data stream into an image: SVG graphics.

Somewhere in the SVG specifications there are codes for specifying a color and how to layout a grid of colors.

AI2 has advanced list blocks that could be combined to transform your RGB byte list into such a SVG grid, and this sample shows how to feed SVG to a WebView for display, without its feet hitting the ground.