Portfolio – dumb question

I really don’t get how to use this.

I created a portfolio page and I created a shortcut.

I added images to the portfolio page but of course, it’s not really what I want. I want something that looks more like the documentation last image. https://oceanwp.org/extension/ocean-portfolio/

The page is http://mirrorstaging.wpengine.com/portfolio/before-after-gallery/?nocache=1

So then I created a shortcut because I see where you can set columns. I set query tab to a category. Not sure what the category is so I set a category on the page above.

I then created a new page with just the shortcut on it using Gutenberg shortcode block.

Nothing. http://mirrorstaging.wpengine.com/before-and-after-gallery-of-mirror-frames/

I must not be understanding something basic here…..

I want to really tag/categorize a bunch of images in the media library and have those shown in the portfolio shown in the documentation.

Sorry for the dumb questions