Can anyone tell me me what this means?

Guys so yk how the teachers before the exam starts take 2 students randomly to put their signature on the file that has the papers before they distribute and open the file ? Can anyone tell me what its for ? For your information, I sit at the second last bench and She took one student from the first bench and then came to me. It was very weird cus she was staring at me from the beginning of the exam but i wasnt acting suspicious or anything