Very long story and 3 levels of phone support later, we concluded that I couldn’t do that unless I had a 2012 Mac or later (2013 Mac Pro or later).
AirDrop doesn’t work between older Macs and iOS. Photos through a USB–Lightening cable doesn’t work unless I don’t want audio with the video.
I could upload it to Facebook and record it using SoundFlower or other hack. Really — that’s it???
The solution? My other daughter came home. I used AirDrop to copy it to her MBP and then used sneakernet to our iMacs.
Jeez...

OS 10.13.4 killed my 2nd external monitor—I need three screens for my day job. 10.14 will not load because my GPU cannot support Metal.
Somehow, I don’t think my kids will get me this for Father’s Day. Dang!
https://www.apple.com/shop/product/G0UR ... 5K-display