Possible to add files from asset library to portfolio?

Is it possible to upload files from your asset library directly into your portfolio? I can add files from my computer to my portfolio, and from the asset library to any page I want, but I can't find the functionality to add files already in the asset library to the portfolio.

It's making the portfolio feature awkward to use/setup because I am trying to get current images off my mobile phone and onto the web page easily. Normally I upload them directly from phone to asset library, then I can freely choose them when adding images to a page. I don't want to have to download the files off my mobile phone to my computer first; this is an awkward and time consuming step.

Please advise. Thanks!