How to read a before-and-after photograph

• The before is flat and overhead-lit; the after has soft, frontal, slightly warmer light.
• Hair down and across the face in the before, tied back in the after.
• No makeup in the before; makeup, or at least a tinted sunscreen and groomed brows, in the after.
• A neutral or downcast expression before, engaged eyes and a slight smile after.
• The chin is higher in the after. Check the ears and the hairline against the background.
• A different crop or zoom, so the two faces are not the same size on the screen.
• Wet, oiled or highlighted skin in the after. Surface reflection reads as skin quality and comes out of a bottle.
• Retouching artefacts: a straight background line that bends near the jaw, pores that vanish only in the second frame, a mole that has moved or disappeared.
• No stated interval, or an after taken immediately post-treatment, where swelling is being presented as volume. Filler photographed at day one looks better than it will at week three.
• No mention of how much product, how many sessions, or what else happened in the same period. A pair spanning eight months during which someone also lost weight, started a retinoid and had three laser sessions is not evidence about the one treatment being advertised.

• The interval between the photographs, and the date of the last treatment before the second one.
• What was done: the product, the quantity, the number of sessions, the settings where they are relevant.
• Whether anything else was done in the same window.
• Who performed it.
• Skin type, where it changes the interpretation.
• That consent was given specifically for the way the image is being used.

A pair that cannot state those things is decorative rather than evidential, and should be read as decoration.

Two reasons. The first is consent. A photograph taken for a clinical record is taken under one consent; publishing it requires a second, specific one, freely given, revocable, and asked for well after the treatment rather than in the flush of a good result. Plenty of people say no, which is entirely their right, and it means some of our best outcomes are not ones we can show.

The second is that we discard pairs where the conditions drifted. A photograph taken in the right room, on the right camera, at the right distance, with the light where it belongs, and one taken hurriedly by a window in November are not a pair — even when the improvement between them is real. We would rather publish six honest comparisons than sixty flattering ones.

It also means our gallery over-represents the treatments people are comfortable being seen to have had. Laser and skin work are well represented; injectable results are consented to far less often, which skews what any clinic can show and is worth holding in mind when you compare two galleries.

There is more on how the photographs themselves are taken and stored in Why we photograph everything.

A still photograph is silent about the thing people most often regret, which is whether the face still moves. An overtreated forehead photographs beautifully. If you are considering a neuromodulator, ask to see a short video of someone raising their brows and smiling after treatment — or ask the practitioner to show you their own face doing it.

Do not ask to see the best results. Ask to see results for someone your age, with your skin type and your particular concern, and then ask to see one that did not go especially well. The answer to the second half of that question tells you more than the entire gallery.