What effect does the 'Hide main image in details panel' toggle have?

When creating a post in StaffCircle, you will see a toggle on the initial creation page after the image has been uploaded:

If the Hide main image in details panel toggle has been left switched on, then the image you have uploaded will not appear in the pull-out drawer when a user clicks on the post:

However, if the Hide main image in details panel toggle has been left switched off, then the image you have uploaded will also appear in the pull-out drawer as when a user clicks on the post: