The 4-Part Pattern Turned Into a 3-Part Pattern

 Photo date: November 11, 2020. Photographer: Mark Mahin.   

I took the photos below while photographing only ordinary drops of pure, clean water falling in front of a black featureless background.  On this day I got a great abundance of pattern repetitions, which occurred in the form of more than five different patterns. One pattern was the four-pattern shown below, which persisted for almost all of hundreds of consecutive photos. 

The pattern then lost one of its features near the top, and turned into the 3-part pattern shown below, which persisted for almost all of hundreds of consecutive photos. On some days these inexplicable patterns gain a feature as my photography of them goes on, and on some days they lose a feature.