For example, I beamed a Z1s photo to my G2. Image looked underexposed (dark) on the G2, perfect on the Z1s. Same image sent to my wife's iPhone 5, same result as the G2 (underexposed).
Beamed an G2 photo to the Z1s. About 2 stops overexposed (bright), loss of detail in the highlights and overly exposed noisy dark areas in the photo.
I've tried this with half a dozen photos taken/viewed on both devices with X reality both on/off, and different screen brightness levels. All images appear to be over exposed by the Z1s display, to the point where I saw shadow details that were not visible at all on the G2.
I realize there's a difference between the IPS panels used in other devices and the TFT LCD used in the Z1, but as far as I know this should only affect viewing angles and some color accuracy. Overexposure seems to be something the Z1s display drivers are doing.
I haven't seen this particular display attribute mentioned here in the forums, so I'm curious if anyone else has made direct comparisons of identical images viewed on a Z1/Z1s and a different device. Now, some of you may see this as a feature of the Z1's display, but not knowing what my friends/family will see when they open their inbox or click a social media link is definitely a minus in my book.