The egg looks perfectly cooked, but you can make it even perfecter by letting it simmer in a low salt soy sauce + saké mixture (50/50). Take your soy saké sauce, add a teaspoon of sugar per cup of final product, and boil it for a couple of minutes. Once it has cooled down, put your soft-boiled eggs in it. You can start eating your eggs after 6 hours. Don't let them sit in it for more than 3 days, though !

It doesn't sound like much, but it makes all the difference.