Bring a printout of your Abstract (including the title) to class. (Put your name on there as well so that it may find its way back to you easily.)
Make it the best version of your Abstract you can muster, because the better it is the more useful the comments will be. Abstracts can be improved endlessly!
You will get 25 minutes to review your fellow peer's Abstract. This should give you sufficient time to think about your comments before you write them up by hand for your fellow student.
The purpose of this exercise is to get some experience in giving feedback to others on their writing, and some practice of the Abstract-organizing principles we follow in this course.