Silent Image Components:
There used to be herds of animals that had fleece. Fleece was easy to find anywhere. So in ancient times this spell was cast with a bit of fleece. The caster would move their finger in the fleece to create the image. Basically, the caster needs a reusable place to create the image. In a pinch and if the caster does not need the image to move, you can use a piece of paper and ink. Smart casters have used the sand on the ground next to them. this works great, but the caster cannot move as the sand spot if where the image is drawn. A special bit if material can be created using down and making a surface similar to fleece, that the image can be drawn within and changed as needed.