I find it impressive that Regular Show was able to cut so quickly from season 1-2 to modern within one season. The change happened so quickly that season 3 of Regular Show has no identity of it's own, the first 15 episodes feel like season 1-2, and the rest of the season feels like modern Regular Show. Adventure Time's change was so gradual that it was impossible to pinpoint exactly what episode marked the change. There were a few episodes in season 3 that did feel and look like season 1-2, Hitman, Still, Conquest of Cutness, and Memory of a Memory felt like season 2 episodes for example.
As for the spongebob image, it looked pre movie, it honestly looks as if Born Again Krabs had a deleted scene.