How GPT Image editing works
GPT Image edits by making a new picture from your photo and your instruction. It is not a brush that paints over pixels: the whole image is drawn again, guided by what you uploaded. That is why it can relight a scene or move an object, and also why small details can shift if you do not ask the model to keep them.
The most reliable edits name one change and list what must stay: “Replace the background with a white studio wall; keep the face, hair, pose and clothes exactly the same.”