This kitchen is stunning for a host of reasons, not the least of which is its perfectly balanced use of dark colors in an otherwise white room. Spreading around those dark colors makes this island appear to be larger and, at the same time, expands the whole room.
An island such as this is going to have activity going on all around it. The lighting needs to do its job while not creating a barrier. If you're lighting an area that people will stand around, the pendants should be high enough so that people can see each other, but no so high that those same people are blinded by light bulb glare.