These two buttons are responsible for "blushing" the image in the standard contort zone. The right button means converging the colors within the contort zone towards the reference color.Regard it as a form of ‘smearing’ the picture with a particular color. This feature can be used to remove blemishes so long as the reference color is set to the general background color within the contort zone.
The leftmost button does the opposite, meaning it 'diverges' the colors within the contort zone away from the reference color.Regard this as a form of contrast enhancement with a complementary color tint to the reference color.
The bottom two pictures have been modified by blushing to lighten up the sea and finally to lighten up the foreground features, similar to a camera flash.
Note that the reference color can be set up manually in CONTORT from a dialog box or it can be set up by sampling the picture by wiping the mouse across it while holding down the right button.