This mini-lesson is important because people might be assigned things that they don't know how to do, and you may be the only one who knows how to do it. If you didn't tell people how to do whatever they are failing to do, the entire class will have missed the assignment. If you are able to do a mini-lesson on any of the technology tips, anyone who didn't know would now come to you for help, and would then succeed.
This mini-lesson makes us a student led classroom because if we didn't do mini-lessons, the teacher would have to tell us how to do it, making us a teacher-led classroom. We are a student led classroom with this mini-lesson because we can show others how to do things that the teacher can't show us.