This was the perfect card for Joel because it's about negative thoughts, imprisonment, and self-imposed restrictions. As we all know, Joel is extremely talented at self-denial and setting limits for himself. That's why he's tied and blindfolded himself here.
However, if you look carefully, the ties aren't that tight. He could easily remove his restraints if he wanted to. But he doesn't want to, since he believes the world is more boring and unfulfilling than it actually is. That's why it took him so long to admit his feelings for Malka (and let himself love and be loved).
Joel is naked because his self-denial is connected to his sexuality. As "the modern Tantalus," he is tempted by his sensual desires and longing for connection, but he prevents himself from doing anything to satisfy those desires because he thinks they will bring nothing but dissatisfaction. He's seen far too much of his parents' dysfunction (and that of Malka's parents, as well) to believe in love (or so he thinks).