That's a small chisel tip, nothing special.
And yes, that's flux from a pen.
If you got all the right stuff (ideal tip, ideal flux pen, ideal solder, steady hand, steely nervers, lovely day, being in a good mood, ...) you surely can do it like that.
It's really artsy and needs lots of flux and experience to get it.
Note that he drags the SIDE of the tip along the pins, that's due to the heat not being right in the tip.. the smaller they get, the more apparent this will become to you if you solder a lot.
Personally I'd use 0.5mm solder wire from a reputable source and a chisel tip instead of the dragging method if this is a one-of.
If I'd do more I'd rather reflow..
PS: and get a microscope (or at least a head magnifier), you'll need 2.5x or better..
PPS: stuff like this is being discussed in the eevblogforums as well. Example for the microscope..