reply to artisticcheese
Re: Are cracks in retaining walls cosmetical? If it's cracking, it's because it's moving.
I wouldn't worry too terribly about it, as it doesn't appear to have moved much. I don't understand why they created the split in the wall though. It appears that the left and right parts of the wall are only connected by that large (and weak) mortar joint. That created a weak point in the wall.