Nice, plump, healthy looking lithops. The leaf markings and color are also good for this time of the year. Another nice thing about growing in a greenhouse, you probably have few insects crawling over and nibbling at the plants. By the end of summer many of my lithops have damage due to grasshoppers and crickets.
With the greenhouse doors open things do get in cats, birds, frogs. I had bees making a nest in a pot but I can see the problems with growing outside.