My understandind is that the pictures shown to the public were taken with a cell phone. There may be others. Pictures always require testimony from witnesses, unless, I suppose, they were taken by security cameras and taken as evidence by the police. Digital pictures are routinely admitted as evidence if they are supported by testimony.
I think there are going to be multiple independent lines of evidence supporting the timeline.
I'm not 100%, but I think the photos were taken with a digital camera. At least, that's what the defense originally said, according to Dan Abrams, when the it first came out that the photos existed.