The meanings of each symbol are as follows:

Green Dots: One green dot symbolizes that it is a photo i believe could be useful and is a good representation of what I am trying to display. Therefore the more Green dots, mean the better i believe the photo is.

Black crosses: A black cross through the photo means i dont believe it is effective in displaying what i am trying to and i do not want to use it.

Red line and dashes: Areas that are shaded in red below or above the line with dashes are places i believe that photo should be cropped to, to improve its appearance.

Here are some examples of other contact sheets made by other photographers: