TomP, GerryB, The reason for the "new" deception, was mentioned earlier in the thread. When the trees are removed from the backdrop, it skews perception, similar to NOT having a backboard on a basketball standard. Likely the slight elevation changes and scale, are responsible for the illusion, too.
RTJ Jr.'s Cochitti lake course has quite a few greens that I thought might have been skyline, at one time. They were all just slighly off, which made me wonder if settleing wasn't responsible for being able to see just a glimer of terrain in the distance.
Rick Phelp's Antler Creek uses creative fairway shaping and angles to either provide, or deny, the greens visibility. A great effect (feature, design element) on a relatively flat site.