What do depth and distance do to a .mpo file?

[J31989508agu9]

Recently have been taking photos from a Nintendo 3DS and plugging them in photoshop. They save as .mpo files and when opened in photoshop there are some options I'm a bit confused by exactly what they do. Under the properties tab, I can change depth and distance, as well as check/uncheck a box that says "stereo." I notice the image changing but I'm curious what is actually happening to it to make it look different.

Thanks in advance