It looks to me like he copied the image I created and posted here two years earlier (https://marmocet.deviantart.com/art/Flag-of-a-Scandinavia-Oriented-Germany-346801450), then just elongated the field a bit and called it his design. He then made a few iterations of that design in which he just reversed the colors. You can see his description of the flag is basically just a paraphrased rewrite of the description I wrote.
I think this is a candidate for deletion, but to be honest, I haven't edited this site in so long that I've forgotten how.
Edit protocol. I ran a poll on Flags and Vexillology to try and determine whether some of the plagiarised posts (noted in Missouri) by a certain contributor should be removed - the result being 7 votes for removal, one vote to have them retained, one vote to have one design in particular remain. Thus I believe all 4 designs should be removed and beyond that the designs in other pages should be thinned by pro rata 7/9th if they add little towards the furtherance of a better flag design.