Anakin knew that Luke was aware he was there, but still he had a hard time actually going beyond the doorway and Force. When Luke called to them he peered around the corner with his mother. He had Luke's blue eyes, but a quiet nature that reflected Leia's own. He was just fine being alone as far as friends went. He had Jacen and Jaina. It reminded him a lot of when he grew up on Coruscant. Back then his only friends were he twins and the droid See Threepio.
He was very smart. At the age of five he was able to take apart computers and solve difficult word puzzles with his mind. His favorite types of puzzles were machines, he considered them like puzzles. Pulling them apart and figuring out how to put them back together was fun for him. With Elena's disappearance he found himself tinkering with things again. Not very concerned with making new friends like most boys his age might have been. No, Anakin had to feel useful and without her it was like he was unsure of how to regain that usefulness.
The healing of Luke had helped some, but still the art of healing was not his favorite thing to focus on. He'd always believed that the Force was a weapon for the Jedi and put more attention on that aspect of it.
Being around Luke had brought back memories. Bittersweet ones of the Jedi Academy and his first days of training. He remembered arriving on Yavin 4 where his Uncle Luke waited for him in black Jedi Robes and showed him the temple that would be his home while he trained to become a Jedi Knight. He remembered the speech he gave in the Grand Audience Chamber of the Code and just looking at him caused the boy to smile more genuinely and step a little further inside the room. He looked at Luke curiously while his mother spoke. Still he stayed closer to Leia and simply observed.