I can see the video of drag and drop images and it looks interesting this reminds me of google docs where if the permission is granted by the owner of the document then the receipient can work synchronously on the same document with the owner or the interactive whiteboard like collaborate.
This is promising because we do not have such a built in component in Moodle at least not that I am aware of. Though I could not find any way to test your collaborative tool.
A work around to your idea.
I recently added a link to google docs powerpoint file from my moodle course on Probability so the learners in the group can modify and work on the document. The plan was to create an informative power point slide on Probability which we could publish on the internet. I had set out an introductory page and given them guidance in our face to face tutorial session. The age range of learners is 13 to 15 year olds. The aim was to motivate my learners to work collaboratively from home and encourage them to be more in charge of their learning.
Its been 3 to 4 weeks since I set out this experiment but so far very little activity has taken place. The lesson for me in all of this is unless they are working towards a specific measurable reward like increase in grades, then most youngsters and indeed many adults will not bother.
So my observation is that collaborative tools are useful in appropriate context, depending on the project and the return for the collaborators.
On the subject of drag and drop, I am very interested in creating drag and drop activities to support my young learners to practice labeling a diagrams which ofcourse is different from the collaborative learning but to date have not found anything. I would appreciate if anyone can inform me if they know of any such activity.