The irony of horror
Instead of painting a story that the author supposes will delight and entertain, this artist chose a gnarly story of the undead, depicted it in true gruesome detail, and then showed it to people. Why the ironic use of horror in art? Perhaps the answer is to allow the viewer to work through the under-worldly aspects of their own experience of life, letting people identify with the feelings of fear, regret, and anxiety. Or maybe it was just done to unnerve people, but in any case, it's ironic to horrify one's audience intentionally.
The irony of the undead
Instead of the resurrection from the dead from Christian belief, this vampire (or Vampyre) gets an unholy resurrection. Ironically, the powers of God to raise the dead are confused: who rose Nosferatu from the dead? The undead idea is ironic considering the religious tradition of the West, and it is ironic in its deliberate attempt to scare the viewer about the issue of death, which is already pretty scary it turns out.
The irony of sacrifice
When Dracula asks Lucy for her love, she offers herself up to him to be symbolically ravaged by him (he drinks her blood, but the overtones are of rape), as a sacrifice for her companions who are able to rally and defeat the Vampyre. The sacrificial irony of the plot is a nice pair for the occult themes of the story, which are sacrifice oriented (because of the historical use of ritual sacrifice in witchcraft and alchemy). In another layer of irony, it is still technically love and sacrifice that "save the day," so to speak.
The irony of second death
The story features the depiction of second death, which is ironic because of the final nature of death. The use of death, unholy resurrection, and then death again gives the arc of the story this function: The status quo or "normal" state of consciousness in Jonathan is permanently altered by his experience of vampire and Van Helsing's salvific stake in Nosferatu's heart. The second death does not make them feel at ease, because if he can rise from the dead once, why not again?
The irony of beauty
The story is elegant and poignant with a kind of mythic perfection about it, as if to literally suggest how influential the story would be in modern horrors. The irony of the story is certainly its universal ubiquity, because this put horror on the map, and also because the beauty of the viewer's thrilling, exotic experience is strangely contrary to what one would expect from the story's use of horror and confusion.
