The "twirls" on this page are a relatively easy process in Adobe Photoshop. It consists of taking any image, applying a mezzotint filter, a few radial blur filters, a few twirl filters, a couple of blend mode changes, then a horizontal flip and a vertical flip. This process, and many others like it, I presume, can be found on the internet. Once I've worked this process on an image I usually make some other adjustments; sharpening, An HDR (High Dynamic Range), or other edits in Photoshop or Luminar. I usually finish it with a slight vignette and a border. The fun part is once you've completed the basic twirl process you can experiment with many other effects to individualize your image.
Some of the photographs that I used for these twirls can be found elsewhere on my website.