One of the things that makes the movie so enjoyable is its rigorous attention to the details of living as a vampire, spun at most points for maximum hilarity. It's hard to groom when you can't see yourself in a mirror, for instance, and for a young vampire, learning to fly can be a real hassle. The vampires are aware of fictional constructions of their habits -- they even crib one bit of hypnotic shenanigans from The Lost Boys, all the while mispronouncing 'spaghetti' as 'basgetti.'
The laugh-out-loud moments are often truly gross -- Dandy vamp Viago's problems with tapping the vein of a victim lead to an awful lot of spurting blood, while new vamp Nick learns the hard way why vampires shouldn't eat chips. Meanwhile, 8000-year-old Petyr lurks in the basement listening to his headphones and refusing to attend house meetings. But he's a good listener!
I mean, really one wishes a 'serious' vampire movie would be this well-thought-out. The writers know their vampire mythology. But they also work some ridiculous changes on their sources, whether it's through Vlad's problems with shape-shifting or the eternal war between vampires and werewolves. What We Do In The Shadows is a sheer delight. Leave your reflection at the door. Highly recommended.