Please tell me the structure of the sentence. Are subject and object reversed?
This sentence is considered an inversion sentence. An inversion sentence is when the verb is put before the subject. Since this sentence starts out with a prepositional phrase, the verb is "comes" and the subject has to be the puppy. "A whole new world of sensory stimulation comes with this," would be a more common way to say this sentence. However, the narrators decided to put the adverbial expression (And with this) in the beginning of the sentence. Doing this makes the sentence sound more formal.