Moom 3.2.8 replaced the rectangular resizing grid with a slanted grid made up of hexagons. This was not a design change that we made by choice, but rather, as a response to a patent claim. To quote from that article…

…we learned there’s a US patent that covers resizing windows using a rectangular grid in a miniature preview image. We learned this when the patent’s owner told us they believed Moom’s grid was infringing on their patent.

The hexagonal grid avoids the patent as it's not using a rectangular shape for either the selection or the window representation. We know this isn't ideal, but we felt that "weird grid" was better than the "no grid" or "get sued for grid" alternatives.

Update: While the hexagons are still in place as an option (in Moom's Mouse prefs), the new default is a full-screen grid, which avoids the patent issue entirely.