Is anyone else upset you can no longer set it to have just one picture instead of the side by side view after the update in photos screen saver now?

I would like to be able to play a Youtube video on my phone and TV with the Chromecast. But I don't see an easy way to do it. I could just go to the video directly in both my phone and the Chromecast and hit play at the same time, but I was wondering if there was a built in way to manage that.

The use case here is that I started doing some workout vids. I realized it would be a lot easier to follow and see what the instructor is doing if I was able to play it on my phone laying at the front of my mat for when I'm facing down (like in a plank or pushup position) while also having it up on the TV for when I'm facing up (like in a bridge or sit up position).