It is a little zippered bag. Currently using it to hold stuff from my pants pockets at night when I go to bed.
All of our class projects use scrap material. I had found the inner material while looking for stuff for a different project. I could not find anything that would go well with it, but I think it does well with this bag as a surprise lining.
Edit: I was asked about the pattern, I got this video from the class syllabus. When opening it while not logged into YouTube I got tons of recommendations for other videos making the same bag.
I think it is a variation of this. https://craftingwithclementine.com/packing-cube-2-0/
Edit: I watched part of the video in that and it is not quite the same. The end result does look similar, so that may be a good place to start while I try to recall the steps.