The shows portrayal of Bloodraven is very....Merlin? (recent series or older tv films) or just generally fantasy heavy. I mean it's just some old dude hanging awkwardly in a tree! That tv scene could have been right out of Monty python. I half expected a cackle
It wasn't very clear whereas the book version paints quite a vivid picture of the lord in ruined finery sitting on a throne (it was a throne right?) with roots burrowing through him, add to that the red eye, the birthmark. It paints a picture.
Sure at the end of the day Bloodraven is just an old man in a tree, there to teach the young apprentice, but he's George's version of a fantasy trope which inevitably brings something new to the table as well.
And I think the show didn't capture that at all. Re reading the comments before I realise I'm not really adding anything apart from my own take on things.