Make a small camera-card guide

Complete original supplied record: An invented camera drawing has a square body, one circular front window and two small top marks. The marks have no names. No photograph was taken. First guide paragraph: “This drawing have a front window. It shows a round window on a square body.” Second paragraph: “Find the round part in front.” A writer changes the first sentence to “This drawing has a front window.” Writer note: “I changed the subject–verb match.” No reader has tried either version. The intended reader wants a clue to the front window in the drawing, not instructions for using a real camera.