Not all brilliant people have photographic memory. There is still another kind of memory called eidetic memory. The latter is more common, where people remembers by not just visual photographs, but by sounds, smell, and other senses.
If you realize your child is particularly good with numbers, sensitive to sounds or can hear and reproduce music or sounds, that is not photographic memory because that has nothing to do with visual intelligence. That is most probably eidetic memory.
Interestingly, most people are born with some kind of super memory, which will be gone in due time when not honed. Often, such abilities are left untouched and unpolished, because schools are not structured to nurture such skills. Eventually, most geniuses are 'normalized' into normal people through the current education system.
Parental influence on children in the first 12 years of their lives have a permanent effect. Unfortunately, children come with no user manual. Each child is different from the other. Discuss how to handle emotional and educational needs of your child here.