How does data consumption use for Airplay downloaded iTunes movies from iPad to Apple TV

I have downloaded movies from iTunes to my iPad. I purchased them and downloaded them directly. When I plug the iPad into my TV via HDMI there is no data consumption at all over the WAN source.

When I try to Airplay to an Apple TV 4K latest version, the same movie attempts to stream instead of playing from the local file.

I am trying to understand why the Apple TV forces the downloaded movie to stream instead of playing from the local copy on the iPad.

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I'll add that I have everything setup on the same Home and logged in as the same iCloud account.

I understand that there is a DRM check necessary but why does it try to stream the entire time instead of play the local copy?