>>4475999To me its very subjective and somewhat dependent on viewing conditions. Its such an odd and unexpected effect that I don't necessarily consider it indicative of a "good" photo, just a specific optical illusion that happens sometimes.
I only see the subjects appear to "pop" out of the picture when viewing the images absolutely fullscreen, sitting a specific distance from the monitor, removing my corrective glasses (I suspect my astigmatism *helps* the effect), and viewing them with only my strong eye (closing or covering the weak eye). Then, the effect is real - shit really does look like a stereogram. In all other conditions, I just don't see it. And a lot of the photos that other people say has it, I don't see it. So I don't know if what you call 3d pop is what I call 3d pop.
In this photo you posted the sky is blue-ish and the building is orange-yellow, and as we know blue and orange are two of the most contrasty colors against each other. I'm gonna attribute the 3d pop to that.