Call me anything you want, but I have yet to hear a difference on my DA5ES with panorama mode off or on
I wonder if it really even does something(no I am not into conspiracies ).
"Panorama" is a mode that stretches the front left and right channels more toward the corresponding left and right surround tracks like a horseshoe (And a little like Jim Fosgate's classic "Rock" mode.) Listen to something with hard left or right front images and then switch the Panorama mode on and off.
GregK is correct. It is indeed a subtle effect on many programs--and as you have seen, the least noticeable of the three controls. It can also be less obvious when using dipoles rather than direct radiators in the surrounds.
The idea was to offer another level of surround utility without being so strong as to cause annoyance/fatigue over time.
If you happen to have Christine Aguilera's "What a girl wants", where she alternates L then R channels at the opening, it ought to be very plain what Panorama does there. But I understand there are different mixes of this track. Doobie Brothers "Steamer lane breakdown" is another such case. But it does show up more subtly on lots of other mixes, too.