After changes have been made to enable the auto selection mode (see D375) I realized that the image selection widget automatically selects a bounding box if the image has been removed from the data storage.
I propose to extend the node predicate for the imageSelectionWidget to only allow images, e.g.
m_Controls.imageSelectionWidget->SetNodePredicate(mitk::NodePredicateAnd::New( mitk::TNodePredicateDataType<mitk::Image>::New(), mitk::NodePredicateNot::New(mitk::NodePredicateProperty::New("helper object"))));