That's not Aemond whatsover. That's clearly an elderly and old man. Viserys, played by Paddy Considine, in specific. He's suffering and rotting away from from leprosy according to his actor.

Aemond has been shown in promo material multiple times. Both in his older and younger forms. In his older form he is played by Ewan Mitchell, and wears an eye patch, like in the books, not a mask. His younger self is played by Leo Ashton, and he also looks nothing like Viserys does in that photo.

Why would Aemond be wearing Jaehaerys + Viserys + Rhaenyra's crown? Why would he be using a cane to support himself? Why would he be wearing a mask? And why would he be wearing Visery's clothing?

Even if you didn't know about all of that stuff in the second paragraph, don't disregard the obvious