If your dog is shy – remember the Big round black lenses can be scary. It looks exactly like the big, round threatening eye and animal displays when it gets scared. This can be very scary in turn can be very scary to a dog.
If the photographer is not someone your dog knows well, ask the photographer to stay well away from your dog and use the zoom function if need be.
Excitable Dogs – The Flash and clicking sounds can stimulate excitable dogs to the point of barking or not being able to be still. This problem requires training. Try to get the dog used to the clicking sound without a flash. Do this by clicking the camera and giving the dog a treat. Then repeat but introduce the flash.
Posing the dog – Most dogs in are not used to sitting beside the owner. They are used to sitting in front of the owner. Sitting and staying beside the owner is a behavior that needs to be taught. If you want shoulder to shoulder shots, then help your dog learn how to do it. Ask your to sit beside you (not facing), and give it treats when for holding that pose for a half of a second.
Honor your dog – If your dog is upset over sitting beside another dog it could be the other dog has been shuttling threatening your dog. Reposition, the dogs so they can be comfortable.
Non-Posed shots – The best shots are real life. Get the the non posed section shots