He is like an angel. There's no doubt in Elizabeth's mind about that. He does not look the part, no, but what does an angel really look like? A beautiful, supernatural being with wings? A melodic voice to match its rhetoric? Is it dressed so formally that it would feel less important if it wore something of lesser value? If that is all true, then perhaps Jack Sparrow truly is an angel.
His limbs are his wings, carrying him about his ship wherever he pleases and to stand at the wheel, steering with his beautifully crafted hands. They are strong, but if caught unawares, they will falter, unable to protect him for a moment at a time. If he can no longer stand, his wings will crumple and he will fall, defenseless altogether.
And that voice. His voice. Not beautiful but not gruesome. It is...sensual, if Elizabeth is permitted to say when comparing to such beautiful creatures. Deep but tender, his voice can lull her to sleep. A small whisper in her ear has her wanting to fall into his arms, to lie in his protection. But he is not an angel so he does not always speak like one. Anger, sadness, confusion sometimes trickle into his tone. He has a mouth for vulgarity. He speaks like an angel who speaks like a man.
Jack Sparrow values his appearance little except for one thing. His hat is most important to him, the equivalent to the angel's formal robe. He feels lesser without it. He does not feel like a captain just as an angel does not feel like an angel if it does not have proper attire. He is made of more than just a hat, of course. Dreadlocks and beads, a red bandana, gold teeth, kohl, a flintlock pistol, a sword and many other things make up his appearance but his hat is a treasure. He can captain his ship - crew and all - but what is a captain, without his hat?
But beneath that selfishness, that ridiculousness for a silly hat, is that caring angel of a man. He makes Elizabeth smile and laugh and he knows just how to do it. Maybe brush his fingertips over her cheek like once before or make a crude remark to start a friendly banter. There was a light in his eyes that beckoned to her, dared for her to do more. If she might add, it's never been sweeter to give in.
Elizabeth sees the angel smile now. They are at the Bride, sharing a drink. He sits across from her at their table, watching her with soft eyes. His hat is resting on the table, his fourth mug of rum almost empty. His smile grows as he takes her hand and pulls her close to whisper in her ear. She is his angel. He wants her to stay, to run away with him. And she forces a smile because he is hers but he will never know for she belongs to someone else - a man with no wings. No freedom.
I guess you could say she's cheating on Will with Jack but cant give Jack her heart because of Will. She doesn't want to hurt him since he's still captain of the Flying Dutchman.
Also how I said that Jack treasurs his hat above all else excluding the Pearl is because in the second movie it seems like he really cares about it.