This is similar to the principle of the Partial Overlap idea, but here, the entire outline of the cyan letter “A” overlaps with the magenta background. The slight overlap prevents gaps between colors and strengthens the boundaries of different blocks of color.
Everything in this image is enlarged to make it really visible; actual printing typically does not have large, obvious overlaps like this unless it’s something like pop art or more punk style screen prints that are styled intentionally with overlaps and gaps to create a specific look.