Its a very cleverly produced photo - you see a bit of everything yet nothing at all. Can not see his confirmation very well. He looks croup high to me but could be photo. All his muscle is underneath his neck as well. For a 4yo he is very well muscled in his neck.
I do not like the angle of the photo as it does not show his back end very well. This is where the engine is so I would like to have seen a more side on view.
I agree with lec. I have a gelding from the King of Diamonds line from Ireland originally (and because of this have researched extensively the line). With these horses you need to consider two things- firstly the line is very overbred and they have bred some amazing jumpers and some absolutely awful horses. So i would go and see him but beware that the reason the pic is at that angle is to hide something. I like him from the picture and he looks kind and intelligent. This is the other thing you need to consider with KOD lines- they are often quirky. They can be stubborn and difficult with tempers. However, once harnesed they make great Sjumpers and as i have found can do lovely dressage tests. They can be grumpy and your best friend at the same time. I have to say though they are tough and robust. I like him overall and would go and see him.. If you want more info on the line i can give you much more just PM me. (although i dont know much about Night Nurse)