This is a stretch, but, you could download the pix to the Walmart photo site and have them printed onto Christmas ornaments. When one of our pets dies, s/he gets an ornament for the tree. Just a thought.
I got one of these: https://www.moo.com/us/accessories/minicard-frame.html frames as a gift. The person printed a bunch of photos on mini cards that I could swap in and out at will. (I admit “at will” has pretty much become “never.” But I *could *switch them out at any time.)
You could also make a custom printed picture book. Lots of companies like Walmart, Shutterfly, etc. can make a very nice hard-cover book using your photos. Cheaper if the photos are already digital.
Most of these companies will turn out 2 or 3 copies of the book for not much $.
I’ve done many different photo gifts through the WalMart photo website - ornaments, calendars, mugs, blankets, etc. They’ve all been big hits. You can also do a collage picture - all of the pictures turned into an 8x10 collage and then frame it.
When our son was younger, my wife always ordered calendars made with his more recent pictures to give as presents to his grandparents.
If it must be digital only, “here’s a drive with your photos” is about all you can offer. But you could dress it up a bit. For example, maybe you can set up a website to highlight the pictures in a meaningful way (like a story format or something) and send him the link. Or like Facebook does, make a video collage and share it with him on social media.