An image producer is also called an image owner. An image owner can offer to share an image with one or more image consumers.
An image consumer is also called an image member.
A shared image is an image that an image owner has made available to one or more image members.
Image sharing is not a relationship of peers:
The possibility of sharing is controlled by the image producer, who offers to share with a consumer.
The actuality of sharing is controlled by the image consumer, who can accept or reject an offer to share.
As a reminder of this unequal relationship, images are shared from producers to (not with) consumers.