When my students critique I always explain that critique is a form of self reflection, using others' work as a guiding force. In that vein I would ask the following questions (that can be applied to all types of classes).
1. What do you think the point (or thesis statement, or intent) was?
2. How do you think the person accomplished the task?
3. What would you do to improve the outcome?
4. What would be your next step (or goal) after this?