I tested this out today and think it has a lot of potential for community engagement. The block is installed in the usual way blocks are installed; when you then turn on the editing, add a block in a course and click the configuration icon you are presented with options to decide how you want your block to display: size of image, speed and -usefully - who is allowed to upload - just teachers or everyone.:
The block appears on the course page with a "plus" like icon to add images to:
While it is easy enough to upload images - and to delete them later - I did find it frustrating that they have to be 100% the same size as specified -no leeway at all. I tried leaving out the height and just uploading images with the same width but it wouldn't wash -it thought I meant 0 pixels. Fair enough, as long as we are aware of it.
A great way to display images in a side block let alone in the centre:
I can see schools in particular making very wide use of this!
A couple of points however: although you can choose "all" for who uploads images, I found that students still could not do this by default; you had to alter their permissions to allow this. I also think it would be very beneficial to have documentation in docs.moodle.org for this so other people don't stumble the way that I did.