The picture is invaluable and gives the mom something to hold onto when her baby is gone. It eases the suffering to have the picture.
One friend whose baby was stillborn was not even allowed to see the baby when it was delivered and for years and years she was so saddened by that fact.
We lost an infant son at 3 days of age. He was taken to one of the early NICU's at another hospital immediately after birth. I never saw him alive nor do I have any pictures of him. The only time I saw him was at his funeral and no one thought to take a picture. So I think this is a wonderful idea.