If that person was previously well known to the dog, probably. There is no reason to suspect that a dog's, or any animals' memory, works different to our own
Agree with wildwood but wonder whether ( as a dog has a sense of smell several thousand times our own) the memory would be the smell rather than visual?
I reckon their memory is similar to ours, in as much as remembering those things that are horrid or pleasant. Our dog that we got from Battersea, hated several things for reasons I could never fathom......Asians, West Highland terriers and newspapers. So I guess that some combination of the above must have been instrumental in her earlier life. Either that or dogs have illogical phobias like we do - i.e. I don't like spiders, but not because I've had a bad experience with them.
I've got a 15 year old English Bull Terrier which I started looking after eight months ago when the owners went abroad, one of them came back a month ago and he dosn't recognise her
had a crea of a friends dog for a year or so when living aborad. We swapped care of hima nd when I returned six months later he remembered me, first my voice then my smell.