Editor toolbar fails to conform to size of editing content area

The CKEditor toolbar seems fixed at a single row, even if that row is too wide for the content area, e.g.:

 Edited yet again: I'm unsure if the behavior is different in 13.3, now that I no longer had a 13.2 build to compare it against.  For sure, thought, the toolbar does not stat confined to the width of the editing area, and also it will fold into multiple lines if the window is made narrow enough.