Can I change cover icon for a slideshow?
Is there any way to change/control which cover icon slide that is displayed for an exported Photos slideshow (when viewed in iTunes, Vimeo, etc.)?
iMac (21.5-inch, Late 2013), macOS Sierra (10.12.3)
If you add the exported video of the slideshow to iTunes, you can assign one of your photos as the cover art in the Info panel of the slideshow. This cover art will be used to show the video in iTunes and it will be the icon of the video in the Finder.