Its hard to tell by the picture. Veriegated _____. I agree it could be boxwood or a barberry of some sort, if the leaves are just leafing out and they get bigger it could be a daphne, that would be lucky. Usually their leaves are just meant to be pretty as a shaped shrub, so yes you prune it to the shape you want and let it fill in. If its daphne, then don't prune as often & it will have divine smelling flowers on it once a year.