Hi, I suggest you going to the photo place that is by the passportcentre if possible, they probably know what needs to be done. If you are getting it by the Town Centre (in scarb), there's one on the 1st floor.
I was very frustrated with getting baby passport photos done. Shoppers drug mart didn't have the properly trained staff to do it. They took one and said it should be ok. But when I went to the submit my application, the gov't worker told me the photo was over exposed.
I went back to shoppers, and they couldn't fix the problem so i told them to give me a refund. I went to Blacks and did it again. and went back and forth from the passport centre and Blacks 3 times until they got it right. I wasted so much time!!
Anyway...one tip..don't have your baby wear pink or white clothing. Wear darker clothing as the background is white for passport photos.