This post shows a sample of Adult Vega Gulls (Choshi, Japan, 27 Dec 09 - 4 Jan 2010). Each photo shows a different individual. Certain things are rather consistent (e.g. leg colour, orbital ring colour) but other things are very variable (e.g. iris pigmentation, pattern and extent of head streaking). While there is individual variation, to my eye the average bird is rather more evenly proportioned than Herring Gull, with a smaller head and parallel-sided bill. The post below shows flight photos, illustrating the details of the wing tip pattern of this taxon.