This is the kids' talk I used for Matt 25:31-46.
I had 7 slides: a bishop, a baby, prisoner, church congregation, refugee camp, big, happy family, Mother Teresa.
The gist of the sermon: scrolled through the slides asking if you met these people, would you be meeting Jesus? i.e. Jesus present in them. The kids got it easily, the answer to all of them, yes.
Then we went through each one, and they had to decide which one especially was Jesus present in. The kids here went for baby/family. I reiterated the point that Jesus is with all of them, but that Jesus thought he was especially present to the prisoner, the refugee, etc.