Famous cartoon historian Jerry Beck has verbally stated that he does not like the cartoons where Tom and Jerry were friends or at least cordial with each other, but this was the only exception. (This statement was said during his commentary on the cartoon on the Spotlight Collection DVD).
The first Tom and Jerry cartoon to be re-released with Perspecta Stereo.
An escalator to the heavenly environs was, and continues to be, a popular rendition of the way up after one's demise.
The feline conductor is a representation of Saint Peter, known to be the heavenly gatekeeper. The demonic bulldog is, of course, a representation of Old Scratch (aka Satan, Lucifer, etc.).