The cat (Henrietta )that kept following Gomer appears to be two different cats; the one that's shown on the ground and circling Gomere feet/legs, always appears younger and a darker shade of orange; when Gomer is showed holding the cat, it always appears as an older, slightly scruffy, and lighter colored cat.
While the Marines are standing in formation aboard ship, the water of the ocean in the background does not move - this is actually a picture of the ocean mounted on the port side of the ship.