Although there isn't a direct feature to create borders on Google Docs, there are 3 workarounds that you can use to create that appearance.

You can add a Border to an image in a Google Docs document. Creating and putting a broder is very easy if you follow this procedure.

You can add a border in a Google Docs page using a workaround, since there's no built-in border tool for doing this automatically.

How to Put Borders Around Pictures on Google Docs. Google does not offer a feature that directly supports adding borders around the images inserted into a Google Docs document, as of May 2013.