Reminds me in a very pleasant way of the first type of computer games I ever played, which were text adventures... to have a similar method employed for quest choices like in the mockup would be awesome.
To me this really enhances both the overall atmosphere of the game, as well as the level of immersion into the game; a lot of modern games, even RPGs, feel kinda hectic in the way they present quests or even dialogue - there just isn't the same "Hey player, why don't you just sit down for a spell and listen to the story I'm about to tell you"-vibe around anymore.
I also feel that if the game shows you everything in absolute detail, instead of just hinting at and telling you about certain details, it takes away a lot of opportunity for the player to simply use their own imagination to picture the current scene just the way they like it, the way they think a horrific spider or a wizened old woman etc should look.
That's basically the same difference between reading a book and watching a movie - both can entertain you, but a book, to me, always wins where immersion and sheer "I need to know how the story ends"-ness is concerned.
A lot of you guys might have experienced something similar after having read a book which was then made into a movie... there's almost always at least one character, setting, detail, whatever, where you feel a sting of disappointment because it just doesn't look or feel right.
Long story short: The artwork and presentation of choices in the mockup immediately reminds me of everything I like about reading books over watching movies - it stimulates the imagination without chaining it down to only one possible interpretation.