I was trying to add the image of the writing on the reverse, but am having trouble doing so here as an answer or comment. On the reverse it says:
"This photo is for my dear little son Alfred and I wish him to keep it as long as he lives & may he live long.
It is the photo of his great grandfather and grandmother
James & Harriet Gillard born April 1804 & 1803.
James Gillard was a twin his mother being the mother of twins three times"