Research Colloquium Midterm Report

I'm doing a student research colloquium, and I have a midterm report coming up. I know I've track of and understand everything enough to write anything from the briefest of summaries to spelling out every little detail of what we've done so far. What I'm not sure of is where in between those two extremes what I write should fall. Are picture documenting what's been done so far appropriate? Or just stick to writing out something of whatever length is right?