The trouble with a polished prototype begins when everyone assumes its decisions have already been made. A button has a precise color, a diagram has neat labels, and the spacing looks settled. The conversation drifts toward the few imperfections still visible. Meanwhile, the question that prompted the model may remain unanswered because the model looks too complete to question comfortably.
Before making one, write the question where the whole team can see it. For a booking flow, that question might be whether people understand when they have committed to a time. For a small piece of furniture, it might be whether there is enough room to reach the shelf. These questions ask for different models, different participants, and different kinds of attention.
I use a second sentence to set the boundary. It says what this version will leave unresolved. The booking flow might use plain text and only one available date. The shelf model might use scrap material and have no final finish. This gives everyone permission to look past those choices while keeping a record of what the test cannot tell us.
That boundary needs to be visible in the prototype itself. A polished screen with a tiny disclaimer still looks like a nearly finished product. A rough section placed beside a carefully developed one can make the intended focus easier to understand. The degree of finish becomes part of how we explain the work to other people.
