Well, the first attempt at this didn't go so well. I had tried to get him to distinguish between a photo of Dora and Kai-lan, but it ended up not going good at all. At first, I thought I was making progress, but when trying it again, he was clearly confused and frustrated.
At the time, I wondered if it was something with the photos - maybe he couldn't see the colors or the paper was too shiny, or maybe the images were too small and the dog's lack of visual acuity (they don't see stuff in sharp detail like humans do) might have been issues. So this time I'm going to try it with actual physical objects.
One of the objects will be his little baseball. The other will be his yellow rubber bone (I guess it's rubber anyway).
I'll start by drilling the names of the objects to him and click and treating when he touches it. Of course, I'll start with one object at a time. Not sure at this point how many repetitions at a time I'll do but it will probably be quite a few and hopefully several times a day. Really drill it in but keep it fun and lighthearted with good treats (read: bread).
Hopefully, this time if I'm more methodical about it, we'll make better progress.
With the new clicker I'm using (much louder, and it's a button clicker so my timing is much better), we'll be able to make a better connection as well.