I wouldn't worry about it, he'll show his face to everyone eventually, then he'll get his face right in everyone elses face. Make sure you don't have any smaller gobies in the tank. Bicolor blennies get pretty territorial as they get older.
For the most part they do get a bit skittish if you roar up to the tank. Likely he's probably looking right at you as you stand in front of the tank looking for him. They're pretty good at blending in.
