The bokeh of the 85mm is a little softer, but that's not the most obvious difference. When you compare the two lenses in F4, the 85mm is sharper, and we all know it would be so, because the zoom is at its maximum aperture and 85mm was stoped down to the sweet spot.
The second comparison shows the weakness of 85mm, which is the chromatic aberration, and lack of contrast between 1.8 and 2.5. In this aspect, the zoom takes advantage 200mm F4.
I've said this in another thread but Canon 100mm F2 has much less chromatic aberration and better contrast than 85mm, even when wide open.