I'm still not convinced that he should be searching for that card. It's the facial pose with his eyes up as he's finger searching for the card. He's been using the cards for a while now, since he's been building this. So he knows where the cards are. Right now it looks as if he'd be in a dark room trying to find the card. I would have him stare at the construction because he's so into it, so focused and concentrated. He then taps to find the card, but have maybe two little taps, he's reaching for the card without taking his eyes of his masterpiece, the hand lands once, card not quite there, he lifts hand again for one adjustment, it lands on the card and then he grabs it. What do you think? It seems that if we play his concentration and obsession with his card house then the fall at the end will feel that much worse for him and the audience.
I like how delicate he is now when he puts the cards on. I think you could bring up his body and head a bit more so that there is a clearer silhouette (the edge of the face is right behind the cards). And when he takes his arms back it feels a bit spliney and without purpose. I see what you're going for with the fingers, but I'd act it out a couple times and film it so you can see the timing for it.
Hope that helps!