Both of these shrubs are Corylus avellana 'Contorta' but the one on your right had a straight stem sprout up and was not pruned out. Within 5 years the contorted shrub that was purchased for much money turned into the straight species and does not look anything like its' sister on the left. What a shame!

That is odd. Must have been a bad graft or something strange happened. Does not even look like the same tree.

Your right it doesn't look like the same tree. I'm going to enclose an earlier picture. At first they were the same but the one on the right started to throw up some straight branches which should have been removed but the landscaper had no idea about this shrub so they were left in place and over the next five years one grew into the straight species. It happens. The same thing happens when you have a shrub with variegated foliage and a new branch comes out all green with no variegation. If you leave it on the shrub it will be more aggressive because of more green in the leaves and can take over the shrub.