New recliner and first bark

Jackson was with us for a whole week without making a sound. He was a near perfect pet ... almost like "Robodog" he was totally crate trained. He seemed to already understand "sit", "down" and sort of "stay". He must have been trained to heel because he was always at our feet - perhaps sometimes under our feet. Up to know, we hadn't heard him bark. He did the cute little whimpering, so we figured he could make sounds - he just choose not to. I like that!

A week before we got Jackson, we purchased a new recliner. Delivery was on March 16. To make sure Jackson didn't run out the door (not that he would), we put him in his crate as the delivery man knocked at the door. Nice, he was early. We let him in and inexplicably,  Jackson started to bark.

What was it about this guy that unsettle Jackson? He didn't look particularly menacing.  He wasn't a big kid. But he barked.

The only distinguishing feature was that he wore a baseball cap - a Yankee cap. It was clear that Jackson was not a Yankee fan. Why else would he bark.

As soon as he left, Jackson stopped barking. Hmmm.