Prompting Reflections: Mirrors, Water and Glass

Reflections are the fastest way to find out whether a model understands the scene it just drew or is only assembling a plausible surface. A mirror is not decoration — it is a second, geometrically constrained view of everything in the room. Get it wrong and the picture reads as wrong long before anyone can say why.

Why Models Get Reflections Wrong

A reflection is a rule, not a texture. The mirrored copy has to match the original in pose, clothing, count and position, flipped across the plane of the surface, seen from where the camera is rather than from where the subject is. That is a lot of consistency to hold, and image models hold it loosely. The common failures are recognisable: a mirror image facing the wrong way, a reflection that shows the subject’s front when it should show her back, extra objects that exist only in the glass, a puddle reflecting a building that is not in the frame.

The other frequent failure is intensity. Real reflective surfaces almost never return a perfect copy. Water breaks the image into bands, glass adds its own colour and the room behind it, wet asphalt smears everything vertically. Models tend to render either a flawless second photograph or a vague bright smudge, with very little in between.

Name the Surface, Then the Behaviour

The useful move is to stop writing “reflection” and start writing what the surface physically is. “Mirror” and “puddle” produce very different optics, and the model knows the difference if you let it. Say polished black granite, or a rain-soaked pavement, or an old mirror with silvering loss at the edges, or a shop window at night. Then add how the surface behaves: rippled, still, streaked, half-fogged, scratched.

That second half matters more than people expect, because it gives the model permission to be imperfect. A reflection described as broken by ripples has no consistency test to fail. A mirror described as clean and full-length does, and that is the one you will spend iterations fixing.

It also helps to say what is being reflected, explicitly, even when it is obvious from the rest of the prompt. Wet street reflecting the red and green of the traffic light above it. Window reflecting the street behind the camera. Naming the source turns the reflection from an unconstrained invention into a described object.

Where to Put the Reflection

If accuracy is what you need, keep the reflective surface partial and off-centre. A puddle occupying the lower corner, a strip of chrome along a car door, a mirror caught at an angle so only a slice of the subject appears — all of these carry the atmosphere of a reflection with a fraction of the geometric burden. Full-frame symmetrical mirror shots are the hardest thing you can ask for and the least likely to survive inspection.

Chrome deserves its own mention. Curved metal reflects a distorted whole environment, which is why chrome objects often come back covered in invented rooms. Describe what surrounds the object and the reflections stop being nonsense; leave it open and the model fills the metal with whatever it likes.