Some learning is best experienced through "doing", and the evidence of that learning is best captured by recording.
When students work through a task that requires several steps, requires them to perform something like a song or exercise, or show something that requires a hefty explanation, recording themselves may be the most convenient and most effective means for conveying what they've done. Showing what they've done provides hard evidence for whether or not learners have grasped the concept at hand.
Students can practice prioritizing information, summarizing their thoughts, and pulling out main ideas as they plan their talking points.
Lastly, we know that as a person teaches someone else as would happen in a demonstration, they solidify their own learning.
You might assign a recorded demonstration when...
you want students to focus on performing a task rather than writing about the task.
you want students to summarize.
you want students to show evidence.
you want to enhance or replace an assignment that asks students to explain a process.
Examples