You can view the video clip in full as you would in the exam. You are also free to view the clip as much as you want, and as well as the full clip, shorter extracts are sometimes available with the questions and answers. Video clips are shown whenever you click the dark blue 'play' button:
Video 'play' button
If you want to re-create exam conditions, follow the instructions exactly, do not use the additional clips or the transcript, and refer to the sample answers only after completing the test.