Wow, you really can feel for that poor sailor. That look is quite clearly the expression of someone who has no hope against the temptation and is beguiled to the point of no return.
It's pretty easy to tell that this mermaid is no good right from the start. There's something about those deadly claws which clearly mark her as unnatural and far from human. Yet still, there's a lust in that face which makes the allure quite clear, and looking at the rest of her decorated fish body gives her a look of tragic beauty. The use of those bright aqua scales and markings against the deep blue, and the royal purple blues of her fins are quite a gorgeous sight.
In her eyes, one almost gets the feeling that she regrets what she is about to do, but one can tell that a grim outcome is inevitable from the sight of the skulls strung along from her tail. Appearing deep down in the image, the fate of the sailors before this man is quite evidently a secret which this unfortunate seagoer will never know about. The beams of light streaming down from above ending only on her ornate fins further tell the story that this seductive sea being's beauty is all that will occur to him. The danger here is completely in the dark.
The weather really adds to the scene. The rain manages to suggest both an air of passion and heavy emotions, which fit the scene, and the dark storm clouds give a sense of power, which create the feeling that the mermaid is a creature of magic.
The transition of the hair from outside the water to in it seems a little odd. I love the aqua hair, but it might have looked more natural to have more of the hair appear to float on the waves. This is a fantastic picture, and a very well-made one-panel story.