There are several bugs in combination which make it impossible to change the department logo, especially, if it originates from an internal Qt resource.

The main reasons are:

(1) The internal resource isn't written to disk as the written contents aren't flushed and hence are lost which results in a file on disk with 0 bytes in size.

(2) The QmitkStdMultiWidgetEditor searches the preferences for the "DepartmentLogo" key and therefore traverses up the preferences tree. However it searches only the initial leaf node instead of its parents in subsequential iterations, which is why the (global) preference is never found.