Oliver's party stood up from their chairs to show their respect long before he did. Even if one was unsure who it was that had been named newly a King, an action like that would have been enough to highlight him. Of course, the old Pendragon King had an easier time identifying him, simply by the crown upon his head, familiar enough that the old King could still remember its weight and sensation, as it had once sat upon his own head.
He studied the youth, in the short few instances of withdrawn delay that Oliver presented him with. The defencelessness that he'd shown, in temporarily directing all his attention elsewhere. Mid-stride, casting his attention about the room, doing all that was expected of him, and presented himself with the sort of gravitas that one would expect from a man that was once King, and still the Pendragon man found himself in a similar position to Oliver himself. His attention, almost entirely, was robbed by one thing.