sky in that shot looks like its been edited in.
Anyway first thoughts aside sharpness probable comes from several factors
1) tripod shot - so handshake not a problem - might or might not be the case, depends how it was shot
2) if tripod shot remote release used as well - further reducing any shake
3) most likley shot with a fast (large max aperture - f number at most f2.8 or smaller) prime (single focal length) lens. Can't tell the focal range. Lens is also likley to be a pro end lens
4) highend camera body - helps but not at much as the pro lens above, but still helps
5) sharpening the end result in editing
6) sharpening again after resizing for the internet and posting there.
Those factors will all aid in getting a sharp shot along with making sure settings (like shutter speed) are fast enough to freeze details - with this shot chances are the slowest speed was 1/200 since flash was most likley used and 1/200 is the fastest speed lowerend cameras and sync with a flash - other speeds might also have been used,
edit - looking at more shots I am guessing handheld with a fast prime - the depth of field in that last shot is shallow - a result of using a wider aperture to allow for a faster shutter speed.