How old is your “palm tree” WCO? What firmware version is on it? Was it a beta test model, or what does old mean? Right now “person detection” is done server side in the cloud. Your wco wakes up to a pir detected event and zips the video off to the cloud in the form of a short video. Some how that video is being put through a person detection algorithm in the cloud and then if it passes ( by either positive person identification, or a false positive person identification [leaves, shadows]), you are being notified about that in the form of a “person” event in the event tab.
When the ad says “captures people and animals”, I think that is referring to what the pir sensor is good at and designed for, not actually referring to “Person Detection”, the service.