The upper one seems to depict older uniforms (no gaiters but stocking above the breeches at knee level). Overall, almost same differences as between pre-WAS and ca. 1770 Gardes Francaises.
Maybe the guardie only wanted to show off those snazzy shoe tongues for the parade and put them over the gaiter for that, even though it's the opposite of the intent of the gaiter. They really are nice shoes, and it doesn't look like they'd fit will under the gaiter.