The differences between the images parameters "illuminance-working plane", "illuminance-WP data" and "illuminance-WP view" are:
"illuminance-working plane" - this option generates an image of the room you have simulated. From these images you can select units to display, daylight factors, lux levels, foot candles. You can also produce contours showing each of these unit types.
"illuminance-WP data" - this option shows the numerical results on a grid which can be defined before you run the simulation. To define the grid go to the Working Plane Settings icon at the top of the screen. This option will be quicker than generating the image however you will only have numeric results.
"illuminance-WP view" - this option allows you to increase the size of the image you are generating. You will be able to select the size of the image and the rooms that will be included in the final image.
The related PDF Provides some further informationon the difference between Illuminance Working Plane and WP View.