Google-drive – How to find a Google Document I edited yesterday

This problem happens to me sometimes on my Ubuntu (its a laptop). This usually happens as Google Docs is trying to establish a connection between your computer and Google's servers, so that whatever you type can be saved automatically.

It is "locked" as a safety measure in case a connection cannot be established fast enough and you are about to close the document that you have already been working on (i.e. added content).

At this time Google Docs inserted images doesn't have a URL that users could get from the edit view.

You could publish the document as a web page (see Publish a document, spreadsheet, presentation, or drawing) and get the image URL from the source of the resulting web page. There are more alternatives like add the image to a Google Drawing. You will be able to publish it as a image so you will not have to look for its URL in the source of a web page.