Were the Chinese Imperial dynasties the same thing as the PRC is now?
In the idea that is is "China"? Yes. Same country, different government. The USA was an invention of the 18th century. China has been around for thousands. Regardless, "the amount of time" land has been controlled is a pretty nonsensical way to determine rightful possession of land. The map I made was mocking the original by applying the same logic to the US, given the guy making the original tweet supports the US.
The US's illegitimacy draws not from how long they've existed, but the fact is was founded by Europeans who slaughtered those you lived here prior and forced this onto the least useful plots of land, the Ghettos Reservations. The problem is that many modern Americans refuse to accept that maybe their righteous civil religion may have been founded on blood for the blood god.
The tweet's caption along with the circles+text try and deny Chinese Sovereignty over historical territory based arbitrarily on how long they have controlled it. This comparison is being made by a supporter of the US. The US has possessed it's entire territory for a span of time shorter that was on this map is considered "Not Really China", thus the US has no real claim to it's territory by their logic. The big difference is that China isn't a settler colony who genocided an indigenous population to exist, unlike the US.
Maybe that has to do with the west making it their primary goal in the 40's-90's to sink the Union that was capable of providing good living to it's people and replace it with a balkanized federation run by oligarchs where a woman's only stable job was prostitution.
But the nation of China wasn't founded on genocide. The US was. Without the genocide of the Native Americans, there would be no US.