Jezmeralda made some custom cutout AR Cards, including one with the black background cut out, and one with the colored area cut out, and set to seeing what would happen. Above, red and blue spots in a Little Mermaid blanket are interpreted as Mario. Here, a tree triggers a Link appearance.
And here’s a grey brick surface that shows up as Kirby (?):
So that’s how AR Cards work: the system looks at the color within the hexagonal area.
See also: More augmented reality posts