Boruto might be in awe. He has always known his father as the Hokage, a powerful and respected figure. Seeing Naruto's past full of struggles, loneliness, and determination would make him realize how far his father has come. It could also make Boruto more empathetic towards Naruto and perhaps inspire him to be more like his father in some ways.
Well, he could be shocked. Boruto has grown up in a relatively peaceful time compared to Naruto's childhood. Naruto faced so much rejection from the village, and seeing all that might make Boruto feel sorry for his father. He might also start to understand why Naruto is so strict about certain things like hard work and never giving up. This could lead to Boruto having a newfound respect for Naruto's values.