I thought this was brilliant. For people who weren't sitting up close and perhaps couldn't see the slides well and/or couldn't hear him well. For people who couldn't process as quickly as he talked and would like to go back to the slides later. For people who saw something on the slides they wanted to refer back to later and research on their own. For people who came in late or had to leave early. There are plenty of reasons why someone might benefit from having access to the slides on their own mobile device.
I'm Meronym (https://linktr.ee/CEMeronym). I've been teaching classes in my local kink community since 2010. You can find more of my writings on FetLife at https://fetlife.com/users/120724/posts/806394. I love teaching kink classes, but not everyone can attend my classes. For some of my classes, I'm providing my slide sets here with some of the conversation that goes along with them (you'll have to supply your side). I suggest you start with Dungeon Essentials.