If I ask someone with Floyd Toole level knowledge of loudspeaker-in-room acoustics (which I can with Billy Woodman at ATC), he would tell me that consistent spectral content of direct vs reflections is the key to imaging. If the reflections look very similar in spectral content to the direct sound it will image well. That's why he builds wide dispersion loudspeakers. Narrow dispersion loudspeakers, having different spectral content off axis than on axis, sends spectral energy that does NOT sound like the direct sound on reflection "zones" (love this word Duke, well done). Its all about the sum of these two complex sources of (direct vs reflected) energy at your ears, because when they combine with each other they partially cancel or completely cancel each other. Longer path = longer time= phase shift. This is the idea of nearfeild monitoring in studios, reduce the amount of reflected energy by sitting closer and moving the speakers further from the walls (smaller triangle). Now you can hear more of your monitor and less of the room. Engineers use this idea to help them get a more consistent sound in the different rooms they work in without changing speakers, using EQ or DSP (all of which adds another "veil" to the direct sound). I remember seeing Kevin Shirley mixing about 2 feet from his speakers which were about 2 feet apart. Not so much "room sound" in such a set up.
Brad