It looks like perfectly normal goose poop to me, although it's a little hard to tell from the tiny pic. If they don't get grass, their poop will be soggy.
Food travels fast through a gosling. Their digestive system is built to process grass and a lot of it. Grass poops are usually firmer than other poops due to the high amount of unprocessed fibre in it. Does your gosling have access to grit? It needs grit to process greens.
Try digging up a square of grass turf and let your gosling go to town on it. Your gosling will be occupied with what it loves best: chewing and digging. It'll get the tiny grains of grit that it needs, and it'll get some grass, so you can se how a grass poop looks.
If you can't get grass, try growing some wheat/barley/rye grass for it.