[This is preliminary documentation and subject to change.]
If this bit is set, the control's text is replaced by an icon. The text entry in the database that normally would specify the text of the control is used as a foreign key to the Binary table to point to the binary data needed for the picture. Therefore, such a control has not text associated with it, only the picture. This stylebit should not be set at the same time as the Bitmap stylebit.
0x00080000 = 5242288