All the pictures that are released of Aiko are from the IHA press office, she's as animated as Amalia is in photos taken of Aiko when she's not aware of the camera and she's behaving naturally. Her father has taken photos and video which have been released to the media. Aiko's life isn't that isolated, children have been coming to the Togu Palace to play with her since she was a toddler. Photos were released of Aiko and Masako at the palace with other children having a gym class when Aiko was 2 years old. Once she was 3 she started attending a toddler's group outside the palace 3 times a week, again with Masako. She went to the zoo recently with friends and their families, she also had friends with her at the Disney theme parks. She does seem quite shy in public but this is quite the norm with Japanese children as well as solemn expressions when they're posing for photographs.
The IHA don't control what she sees on TV or the books she's exposed to, also Aiko's parents are trying to give make sure she has similar experiences to other children of her generation, hence the trip to Disney.
The IHA is a large organisation, it's all the people who are employed to look after the various palaces, including the historic ones in the old imperial capital of Kyoto. The medical staff at the hospital in the Imperial Palace grounds in Tokyo are IHA, so are all the gardeners, the scientists who work in the science laboratory in the Imperial Palace ground who work with the Emperor in his research into fish. Over 7,000 people are the IHA so, would they all have a heart attack at pictures of Aiko smiling?!
Masako isn't totally isolated from her family. At the height of her breakdown in 2004, Masako left the Togu Palace with Aiko and went and stayed with her mother in her parents' holiday villa in the Nagano area. ( There is also an Imperial holiday villa in the Nagano area but Masako chose to stay with her parents) Masako spent a month with her mother and Aiko before she returned to Tokyo.