Is it bad to make mistakes?
The brain learns by trial-and-error. Mistakes are as informative, and useful, as successes for our brain. We learn by trial -and-error and by correcting those errors. If you do this in class openly and often, it can help students to slowly overcome their inner hurdles. Downplaying a mistake encourages students to take risks more often, which will stimulate their progress.
Instead of focusing on what isn’t working, students need more to know what they should do next in order to succeed the next step. “And what should I do now?”. This is part of a positive approach of motivation and symbolic reward (words of encouragement and desire to advance).
When you show it to your students, we suggest you show it to them once in full to collect their initial reactions. Then you can watch it again bit by bit in order to go into more detail and gain more educational value.