When Viserys and Lyonel Strong meet with Corlys in his castle, the Lyonel is holding a goblet in his right hand. When they say farewell, the long shot shows the goblet is gone and Lyonel's hand is at his side.
Rhaenyra tells Ser Criston that Aegon the Conqueror "united the Seven Kingdoms" Aegon conquered six of the kingdoms; Dorne is still independent at this point in history, and won't become the seventh kingdom for another 70 years, or almost 200 years after Aegon's war of conquest.