Model the dialogue with the OTE:
S1: "What's this?" (show #1)
S2: "何これ?! Oh, is it a cat?"
S1: "No, it isn't. What's this?" (show #2)
S2: "Hmm, is it a cucumber?"
S1: "No, it isn't. What's this?" (show #3)
S2: "Ah! Is it an eggplant?"
S1: "Yes, it is."
Have the students pair up along desk columns and rotate the columns to switch partners, or walk around and talk to random partners, or race in teams up and down the rows to complete the dialogue.
So many options.