These images are will be displayed alongside the user's display name
on the dashboard. There are several images because different ones will
be displayed at different times of the day and week.
These files are generated during the website's first-run process. They
don't need to be a actual hard-coded part of the repository. The way
the site is set-up, the user will either stick with the
defaults (generated on first-run) or upload their own personal files.
Craig Oates