First of all, its a really great, comprehensive guide to identifying birds unlike any other field guide out there. Usually, these books show an illustrated male and a female, sometimes a juvenile, of each species highlighting identifying marks. With the Crossley guide, each plate is a composite of numerous photographs not only showing identifying marks but characteristic behaviors and what birds look like from near and far and in flight.
But what I like most about the images is how strange they are. I love the cut and paste quality of the collages. Birds in the back of the image are just as in focus as the birds in the front. Not all the lighting matches, the arrangements can sometimes get so crowded that, depending on the bird, it can either feel delightful or like its some kind of bird horror. Sometimes the birds are dropped into scenes like a factory farm, a half sunken cargo ship or what seems to be an industrial age european city. Its sort of both art and utilitarian.