I took the test in PA earlier this year. There is no ID on the test from photos, however, they do ask questions about certain ID characteristics. For example:
Which of the following species has oppositely arranged leaves?
A. Sugar Maple (Acer sacharum)
B. White Oak (Quercus alba)
C. White Ash (Fraxinus americana)
D. Blue Spruce (Picea pungens)
Hopefully, you all know the answer. It would be a sad day when a certified arborist got stumped on that one. Basically the ID questions are simple if you are well versed in the ID characteristics of all the basic tree species in the region (were talking oaks, maples, pines, ornamentals that even homeowners should know, etc) as well as the basic terminology used to describe the characteristis (petiole, pinnately compound, lobed, serrated, palmate, etc). Im sure you know the lingo if you are attempting the test but my point is that it really is pretty easy (almost insultingly easy) if you really know your stuff. Good luck!