The pond is safer for children as it is raised off the ground - it will also keep out dogs or other pets.
There is no need to dig a huge hole in the ground, you can just build around it.
With the pond being higher this helps maintenance, fish viewing*, prevents rubbish, mud and other unwanted things falling into your pond.
*If you are considering a koi pond then this will give you great pleasure for not only viewing the fish, but easily feeding them out of your hand.
This pond has been created slightly above ground but they have blended it nicely with stones and rocks. When doing a raised pond you need to take the cost of materials into account. Where you would normally dig a hole and the earth would support it you now would need to use bricks, blocks or stone with concrete and sometimes even decking.
These types of pond just go so well with patios and I would make sure that you create a wide rim all the way around the edge that can provide an extra seating area. It's as close to the fish as you can get without going for a paddle: )
There is more information on building these types of ponds in the installing ponds section that will help you understand more of the construction side.