Gawker calls Lydia Callis, the mayor's sign language translator, "New York City's Hurricane Crush." Joe Coscarelli pinpoints why she's such an Internet sensation (with Tumblr, YouTube and GIF paeans to prove it):

Unlike Bloomberg's own stilted Spanish, another highlight of the updates, Callis's signing is both lightning-fast and emotive, her animated face lighting up and contorting happily as she goes, not unlike a guitarist during a blistering solo.

Caitlin Wood explains why Callis is so expressive:

Facial expressions are a grammatical aspect of the language and can relay more information than the signs themselves. Many hearing people appeared to mistake her animated signing as being theatrical or over the top, when in reality she’s simply conveying the emotional tone of what’s being discussed.