Hidden editable pixmap control
1. Place a control refnum
2. Right-click, Select VI Server Class, Generic, GObject, Control, Pixmap
3. Now it's a "Pixmap Refnum". Right-click again, Show Control
4. Drag the control out.
Unfortunately, I first noticed this control in the VI Scripting style ring, where it was labeled as "warning: dangerous" or something like that. But the class isn't marked private, and it can be placed in the manner I described without any kind of warning, so maybe that warning is obsolete a
Try to add dialogEditor=true to your LabVIEW.ini file. This worked at least in the LabVIEW 7.x days and still might be present. See here https://labview.brianrenken.com/INI/
for some details about this.