Despite the niceties, I bet actual relations between US and China are rather strained, and China has America by the economic 'balls', so America can't do too much against them. It's also possible that China is anticipating the collapse of the US economy and this is actually 'advertising' for those to come to them to escape the financial apocalypse of western world, maybe. I truly doubt this is merely about "improving relationships" and is merely a cover to soften the propaganda. The ad also seems more structured to attract business types and investors, rather than just anyone. The location of showing this ad is even strategic in nature, and not just for the popularity of Times Square either.