The plate viewer is a data tool that displays the images in your experiment in plate format. Your project must define an image set list with metadata annotations for the image's well and, optionally its plate and site. The plate viewer will then group your images by well and display a plate map for you. If you have defined a plate metadata tag (with the name, "Plate"), the plate viewer will group your images by plate and display a choice box that lets you pick the plate to display.
Click on a well to see the images for that well. Channels are composited together if there is more than one channel and you can control the color used to display each channel. If you have more than one site per well and have site metadata (with the name, "Site"), the plate viewer will tile the sites when displaying.