If you're familiar with Smalltalk, skip the first twenty minutes of that first video I shared and then stick around for at least fifteen minutes, that's where the customizable views are explained. I think that answers your question - although I don't know how innovative this if you take into account all the alternative UI's that failed. However, the way it is being implemented in Pharo really appeals to me, and I can see it really work well in this "visual debugging seeing room environment thingy" Bret Victor wants us to aim for.