I call them coffee images because they usually come into being when I treat myself to a tea or coffee break and experiment a little in Affinity at the same time. Most of the time the result is rather dreadful, like the attached image.
On very rare occasions, however, something genuinely good appears, sometimes even something I would consider truly successful. Those pieces I do not delete, of course, but keep until I can use exactly that kind of image as a background or design element.