Hi,
if it comes to freewriting, you can just write for those full minutes and it's not even needed to edit, use markdowns or add a picture. The only thing that counts is that you let your brain do the work, So no story lines, no thinking first about what to write. If it comes to it a freewrite is easy to recognise.

How? You see, within one text the topic changes rapidly since this is how we think. One word triggers something else in the memory..