Only a little Sparrow?

But can't they ever look appealing when they are young?
 This one seems to be on its own,and very often joins our group of Dunnocks on their food forage?
 At first I thought it was a young Dunnock but as it matured I could see it was not like the other junior Dunnocks.
 This little one is happy with its company and the Dunnocks tolerate it?