It is often said that "one picture is worth a thousand words." But too many photographs just cause confusion.
Photographs create very powerful impressions. In my experience, birth mothers look very carefully at photographs and they do make a big difference.
I recommend using one carefully selected cover photograph. You do not want a "snapshot," and you do not want a studio protrait. If you are not personally skilled in the are of photography, it is well worth hiring a professional photographer. The idea is to create a photograph that says something about who you are. I have seen adoptive couples provide a photograph of themselves on the beach, in the mountains, in a city or by the family fireplace.
It is helpful to have several additional photographs in the body of the profile. These will allow you to show more helpful information and images of your family. Photos of additional family members, the family dog, or "our house" can be helpful, but can also be confusing if not carefully chosen. Above all, avoid pictures taken from your family album. Most people have family albums full of pictures which may be meaningful to them, but which are really terrible photopraphs. Leave them in the album.