This is the place that you can store additional pictures to include in your reports.
You can add and remove items in this list by using the right-click menu.
You can edit the name and choose a new picture by double clicking on the name or picture in the list.
IMPORTANT NOTE: Some reports you load into Martial Class may use Logo items in this list. You are free to change the name and picture for all logos, but if you delete any, then you may break some of the reports.