A timelapse video of the creation of my image "Give me back my pants" from a few weeks backs. Sped up some 25 times. I recommend watching it in 1080p on YouTube.
I didn't make any video captions for this one since they take a lot of time to do and I never heard any feedback about them (so people probably don't watch them). It does show all the wrong starts, corrections and changes that go into a final piece though! This is done in Krita but the process would be the same for Gimp (Krita has a much more powerful all-in-one move/adjust tool than GIMP though, which is seen in some places of this video).
Music by zero-project (
http://www.zero-project.gr, released under creative commons). Final image result by me can be found
here on gimpchat.