Strong
Your mind's eye renders. Asked for a face, a room or a particular afternoon, you get colour, texture and detail rather than a label — and the image arrives without being assembled, the way a photograph arrives rather than a drawing. This is the channel most people assume everyone has, and the assumption is wrong in both directions: a strong picture is not better memory, and it is not a better imagination, it is a different medium for the same work. What it does reliably give you is recognition. Scenes come back attached to their look, so places, faces and the physical arrangement of things are easy to retrieve and hard to describe.
Moderate
You get something, and it is not vivid. Asked to picture a familiar room you receive an impression — the shape of it, roughly where things are, a colour or two — without the detail filling in, and pushing harder tends to produce more effort rather than more image. This is the most common reading and the least interesting to talk about, which is why it is underrepresented in every conversation about mental imagery: the people at the two ends are the ones who write about it. Practically, it means you can use imagery when it helps and are not stuck when it does not arrive.
Faint
There is little or nothing on the screen. You know what your kitchen looks like — you could describe the cupboards, place the window, tell someone where the kettle is — but knowing it and seeing it are separate operations for you, and only the first one runs. It is worth being exact about what this is not: it is not poor imagination, it is not bad memory, and a questionnaire cannot tell you whether it is aphantasia, which is a narrower and more absolute thing. What it does mean is that your recall is propositional rather than pictorial. You hold the facts about the scene, not the scene.