1. Lighting
Look at where the shadows fall and how hard they are. Nasolabial shadows, tear trough shadows and jawline definition all change dramatically with light direction. If the before image has harder, higher light than the after image, a good part of the difference is the lamp.
Check catchlights in the eyes, shadows under the nose, and whether the background brightness matches. Those are simple tells and they are frequently inconsistent.
2. Angle and distance
A face photographed from slightly below looks heavier in the jaw and shorter in the chin. From slightly above it looks the opposite. A small tilt changes apparent jawline definition more than most treatments do.
Camera distance and focal length matter too. Close, wide angle photography enlarges whatever is nearest the lens, usually the nose, and compresses the rest. Stepping back and zooming in flattens the face. Two photographs taken at different distances are not comparable, and there is no way to correct for it by eye.
3. Expression
This is the most common and least noticed difference. In the before image the subject looks neutral or slightly downturned. In the after image there is the faintest lift at the corners of the mouth and a slightly wider eye.
Ask whether both images are at complete rest, or both in the same movement. For anti wrinkle treatment, the meaningful pair is at maximum frown or maximum brow raise in both images, because that is where the treatment acts.
4. Makeup, hair and skin preparation
Base makeup evens skin tone, blurs texture and covers redness. Contouring changes apparent structure. Groomed brows change the whole upper face. Hair pulled back changes the jawline.
If the before image is bare and the after image is finished, you are looking at makeup with a treatment somewhere underneath it.
5. Timing
For filler, immediate images include swelling. For toxin, a fair after image is at two weeks, when the effect is complete. For skin treatments and courses, the meaningful interval is months.
Ask when. A clinic documenting outcomes will know and will say. A clinic marketing them often will not.
6. Selection, and the images you are not seeing
Every gallery is a selection of best results. That is not deceptive in itself; nobody publishes their worst work. But it means a gallery tells you what is achievable at the top end, not what is typical.
The useful question is: what does an average result look like, and can I see a case that did not go as planned and what you did about it. Very few practices will show you the second. The ones that will are telling you something considerable about their confidence.
7. Filters, retouching and the modern problem
Social media platforms apply processing by default, and many filters subtly alter facial geometry as well as skin texture. Retouching that removes pores and evens tone is close to universal in commercial imagery.
You cannot reliably detect light retouching by eye. What you can do is prefer images published with consistent, unglamorous lighting on a plain background, because that is the format a practice uses when it is recording rather than selling.
8. What a genuinely useful pair looks like
Plain background. Same light source in the same position, ideally soft and frontal. Same camera distance and the same lens. Head level, chin neutral, ears equally visible, which is the simplest way to confirm the angle has not moved. Same expression, both at rest or both in the same movement. No makeup in either. Hair back in both. And a stated interval between the two.
Clinics that photograph this way are doing it because they want a record they can learn from, not an image they can post. It is a slower, duller and considerably more useful practice, and it is worth asking whether standardised photographs are taken at your own consultation and whether you can have copies.
One further check applies to any pair used to sell a treatment: is the person in the after image the same person as in the before image. Composite galleries assembled from manufacturer material are common, and a clinic showing manufacturer supplied images should say that is what they are.
9. Take your own
The most useful before photograph is one you take yourself, before treatment, in daylight from a window, at arm's length, at rest, without makeup, from the front and both sides. Repeat it at the same window at two weeks and at three months.
It costs nothing, it is the only comparison that is actually about your face, and it is the single most useful thing you can do if you ever need to demonstrate what changed. It also protects you from the most common experience in aesthetics, which is being unable to remember what you looked like before. Related reading: what a good consultation looks like and reading clinic marketing.