Unrelated, but I love that you discovered this image and worked so hard to figure out the answer to your question. I had also never heard of the Top View community, and it’s so interesting - subscribed! Thanks, OP :)
I think I may have found the answer? After researching a little bit it looks like Abu al Abyad, the island above the elongated rectangles is actually an international military testing facility. This article , and a couple similar to it alluded that the area is for testing naval equipment and amphibious landings.
There are similar man made pools of salt water in desert condition that the US utilizes for radar testing at the China Lake research facility in California.