Google Docs are a suite of office applications and file storage nestled in the web cloud.
Select "Anyone with link" if you want to allow anyone viewing your post to see the image. For more information on choosing share options go here.
Each browser stores the thumbnail URL in a different location. While looking at the file page showing a large image thumbnail, following the steps below for your browser to find the appropriate URL to use in the Google forum Add references search bar.
Right-click on the image and choose Properties. The copy the Address (URL) from the Properties window.
Right-click on the image and choose View Image Info. Then right-click on image address in the window to copy OR copy the Location URL from the Image Information window.
Right-click on the image and choose Copy image URL.
Right-click on the image and choose Copy Image Address.
Note: If someone wants to annotate their image through Google Docs, first create a Drawing document and insert the image into the Drawing file.