Unable to reference existing image when creating a Product via headless API

Issue

I would like to create a product via headless API that uses an existing image from the Document Library.

Currently, it isn't possible to reference existing images when creating a product through headless API. It is only possible to upload new product images.
If you try to use the same image for a product, a new image will be uploaded.

There is currently a story ticket at COMMERCE-11640 to add the capability to reference existing images when creating products via API.