As you have rightly noticed, the concept of microlesson refers to a constructionist rather than a traditional approach to teaching ans it is mainly targeted towards teacher training by providing a reduced and scaled-down situation whereby the trainees pay their full and undivided attention to specific aspects of an otherwise complex concept such as the application of IT-based instructional components. In so doing, microlessons provide students with opportunities for practicing teaching activities by integrating both theory and practice and facilitating the training situation within which the mastery of teaching tasks are of paramount importance. For more information, the following links can hopefully provide you with what you are looking for.