When enabled, Black Point Compensation will be used for the soft-proof profile when displayed.

Black Point Compensation is used to compensate for differences in black levels available on different devices. When enabled, it makes adjustments based on the differences between the color profile of the image and that of the output device, as represented by the soft-proof profile.

To get an idea how your image will look with the soft-proof profile enable View → Color Management → Proof Colors.