Today the layerlist widget changing the layer attributes instead of the layerview attribute, for example the visibility or the opacity.
Also if you add a mapimage layer with sublayers, you don't get sublayerviews. (A GroupLayerView doesn't exists today)
The problem is when you have two views on the same map, and want to turn off/on a layer/sublayer, it will turn it off/on at both mapviews. But the layerlist is connected to a specific mapview.