Before-and-after is the highest-risk format on this marketplace, and the risk is not in the filming. It is that the format itself asserts causation, and the assertion is yours to substantiate whether or not you phrased it as a claim.
What to put in the public brief
- The elapsed time between the two recordings
- That both must be filmed under matched conditions
- Whether they must appear on camera
- Any eligibility, stated plainly and non-medically
- That an unchanged result is paid the same
Keep the product identity private, particularly pre-launch.
What to put in the private instructions
Fix the shot conditions in writing
Same room, same distance, same light source, same time of day, same clothing. Ask them to photograph their setup at the first session so they can reproduce it at the second.
Say what may not be changed
No filters, no editing, no beauty modes, no different camera. Phones apply processing silently, so ask them to note the device and keep it the same.
Ask for a dated marker in both frames
Something ordinary and current. It makes the interval verifiable without asking anyone to hold up a newspaper.
State plainly that no change is an acceptable outcome and is paid
Otherwise you are paying for a result, which is how fabricated before-and-afters happen without anyone deciding to fabricate one.
Proof worth requiring
Ask for
Both raw files, the setup photograph from session one, the device, and the dates.
Do not ask for
A more dramatic second take, a different angle "that shows it better", or any retouching. Each of those converts documentation into advertising you cannot support.
Before you run this at all
Ask whether you can substantiate that a result like this is typical. If you cannot, you need a prominent qualification, and a qualification that appears only in a caption is not prominent when the content is a video.
If the honest answer is that results vary enormously, a testimonial lets a person describe their own experience without the format asserting it will be repeated. That is a weaker claim and a defensible one.