Picture: a visual representation of an object or scene or person or abstraction produced on a surface by some one (painter, artist, learner etc)
Photograph: a representation of a person or scene in the form of a print or transparent slide; recorded by a camera on light-sensitive material
So all photographs are pictures, but not all pictures are photographs.
Pictures can be paintings, serigraphs, pen and ink drawings.. Have a look at this sentence:
That is a picture of my grandfather panted from his photograph by a great artist
You must say: I saw your Photo in your profile, because it is uploaded from your photograph.
Student or Learner