Progress pictures that show the change
The most common reason a progress picture disappoints is not that nothing changed. It is that the second photograph was taken from slightly further back, slightly higher, in different light — and those three differences are larger than several weeks of change.
01
The camera moves more than you do
A step closer, a phone held at chest instead of waist, an arm extended a little further. Each is invisible while you take it and each one outweighs weeks of difference. This is why a reference photo held on screen beats trying to remember.
02
Light before angle, angle before pose
Shadow is read as shape. The same body in overhead light and in window light looks like two different bodies, which is also why photographs taken in a gym mirror and at home never sit together. Fix the light first.
03
Photograph on a schedule, not on a feeling
Photographs taken on good days are a biased series. A fixed day and time gives you the boring, honest version, which is the one that shows a trend instead of a mood.
Weekly is usually right
Often enough to build a sequence worth playing back, rare enough that you are not looking for change that has not happened yet. Nothing here is advice about your body — it is about photographing it so the photographs can be compared.