The blockchain provides an immutable public record. Yes, not necessary but still an interesting approach and actually a decent fit for a blockchain. A blockchain might still be an over fit but it's useful if I claim to have an undoctored video at a certain point in time but don't want to release it, immediately, and need a distributed way to validate that claim.

> And as mentioned in the above comments, it does not help with analog loopholes and trust in the person being photographed.

Like I said in my above comment, it doesn't solve all of the problems but at least we can begin establishing a record of source.