The main reasons for the unsuccessful result
If the face is dark, the object is cropped, there are too many people or the request asks to replace the background, clothing, posture and style at once, a model begins to guess details.
It's better to run one task at a time: first improve the photo, then replace the background, and then poster style, so you have a higher chance of preserving likeness and important details.
What to try?
- Choose a photo with the best light and one main object
- reduce the prompt to one task
- make a series of choices and compare the results
How to get a reliable result for mistakes
Start with one clear source image and one main change. Name the face, object, angle or color that must remain unchanged.
For a complex idea, split the work into steps and compare the first result before launching a full series.