I've seen pictures taken of lenticular clouds that look more like a flying saucer than that image in the photograph, but they aren't aricraft and wouldn't even be categorized as UFOs by MUFON.
I agree. It also looks like a solid craft being piloted through the air. Fact is, it's impossible to tell what that object is from our vantage point.
Just once, I'd like to see someone get some clear, unambiguous, close up photos of one of these things. I've read reports many times of sightings of enormous craft - some described as a mile in length or longer. Wouldn't it be nice if just one of the people making such a sighting, got a few snaps off before it disappeared?