Courts act on evidence. If a party lacks evidence to support his/her propositions or allegations, his/her case will fail.
Evidence can take many forms. The commonest form, indeed, arguably, the only form, is oral evidence.
The general sense in lay people (non-lawyers) that something more than an oral account is needed to prove a fact, expresses anxiety about the frailty of the oral account.
That general sense is, often, a hankering for corroboration, as in “…yes, I took the bus home that day, here is the ticket showing the date, the time and the route number”. Here the proof is not the ticket, it is the statement, “I took the bus home…”.
Bus tickets are usually without problems, but photographs and video or other digital media are not. Even before the arrival of digital cameras, photographic images were capable of being manipulated in the darkroom. With digital media the problem is acute.
The visual record must be proved and evidence must be, generally, available to eliminate the possibility that the record has been tampered with.
That aside, visual records are treated as “real evidence”. A typical item of real evidence would be a defective consumer good, a television, say, or a motor car. The item is, in theory, available for inspection by the court. Oddly, the court is likely to prefer a report on a motor car and/or a television, whereas the court is likely to prefer its own inspection of a visual record over a gloss or explanation from an expert as to what the visual record shows.
Because of the requirement that the integrity of the visual record be proved, it may be possible to exclude a visual record where that integrity is not secured.
This may be the wisest course; visual records are not always as easily understood as people, including judges, think. Take the common case of X-ray films. It takes a great deal of experience and talent to “read” an X-ray. That is evident to most people, but the interpretative faculty for reading an X-ray is simply one instance of that faculty for “reading” visual records. If the integrity of the visual record cannot be proved, who exactly is to hand who can prove what is recorded in the image?