The goal of this activity is to get the students to practice "I think (that) ~~ is ~~" a lot by giving them an adjective and then having them try to think of a topic that will make their friends say it.
I demonstrate with the JTE in front of the class first. I write an adjective like "cool" on the board and cover it with my textbook so the JTE can't see it. Then I ask them "What do you think about (a younger male teacher at the school)? What do you think about Nishikori Kei?" and so on until they answer "I think that he is cool." I usually do this with 2 or 3 more adjectives until the class understands the idea.
Next I pass out the worksheets (there's 2 per page so I cut them down the middle) and assign each student a number from 1-9. On page 2 you'll see a list of adjectives I use, which I write up on the board. Students with number 1 use "good," students with 2 use "bad," and so on. Feel free to change the adjectives as you see fit or let them choose their own adjectives if that works better. Once they have their adjective, they need to think of a topic that will make their classmates say "I think that he/she/it is ~~."
Once everyone is ready, the students get up and ask each other the "What do you think about ~?" question. Students can answer with any adjective they like, including ones that aren't on the list. In the end, I check how many of their classmates answered with the adjective they were hoping for, but any answer is okay, of course!