^^^ The building that peers through Marina City in the rendering is not RiverBend. That building is actually the Left Bank at K Station. The Left Bank is 365' high.
http://www.emporis.com/building/left...chicago-il-usa
River Point is supposed to be 650' high.
http://www.emporis.com/building/left...chicago-il-usa
The Left Bank is right across Canal Street from the north portion of the River Point parcel (where the boutique hotel, now removed from the plan, originally was going to be located). RiverBend is further north and not in the rendering.
650/365 = 1.77. So, River Point should look 77% taller than the building that appears next to it. It doesn't. The perspective in the rendering makes River Point look shorter than it will be. I don't think it has anything to do with Reilly's skyline vision for Downtown.