Thirty-seven thirty-seven 37s
Consider a mosaic like this one, which has 37 individual 37s, arranged according to a particular template (some bigger, some smaller, etc.). Do this a total of 37 times, each one with the same 37 subtiles, but arranged in the template in different (randomly generated) orders. Now you have 37 different but similar mosaics; use those as tiles with the same template to create a meta-37-mosaic. That's what you see here.