We have many accounts of Conquistadors first seeing the cities of Mesoamerica and the Andes, and marveling at what they experienced. But are there any accounts of the reverse, of Native Americans first traveling to Europe and reacting to what they saw?
We know that that there quite a few natives went to Europe, such as Pocahontas and Garcilaso de la Vega, but I couldn't find any accounts on what they actually thought of what they saw. Were they amazed? Curious? Disappointed? Do any accounts survive of such first encounters?
One case that comes to mind comes Tomocomo, a kind of companion who journeyed with Pocahontas to England. Allegedly he carried a walking stick with him upon which to keep a tally of all the people he saw, but soon gave up because there were far too many people in London or he was tired by the difficulty of the task.
Sadly, as far as I'm aware, he didn't leave a written account of his experience. He appears to have been disappointed by not being given a gift by the King of England and was met with a light degree of curiosity by those who saw him.
It's important to note that the Natives weren't exactly stupid. They would most likely grasp the concept of a king fairly easily as well as extraordinarily large cities. The Europeans, meanwhile, while possibly looking down on the Natives as "Savage" or "Ignorant" wouldn't likely be that amazed by "strangely colored aboriginals".
It's unlikely that it would be akin to, say, seeing Aliens come to earth for either side.