steam+monkey

To me the "steam monkey" represents all things old. When it talks about a wind up monkey, a gas monkey a steam monkey and finally an electric monkey, i think that it represents replacement and moving on. I think that that is the main purpose of the poem is to show feelings of regret, and maybe even resentment towards the "electric monkey".

Excellent observation about the notion of resentment - I agree entirely that the tone includes some resentment towards what is new.