Looks like it is not awake yet. They may look bare in the winter, while dormant. But it depends on where it was being grown. Down here in TX, they keep their foliage when we have mild winters or if you place them in protected locations. Up in Indiana, where the G Farm is, they loose all foliage.
My Pee Wee for example, kept all the foliage this year in its protected location even though we had lows in the 13-15F range. New foliage has been leafing out for the last few weeks so it now has a mix of old and new foliage. Other oakleafs lost all their foliage or almost all of it but they too are leafing out now as well. The Alice Hydrangeas and Pee Wees that I saw at a nearby botanical garden did loose all their foliage. Once bigger, you may notice that the bark tends to fall off during the winter months; I do not think it does much of that when small. You should get better foliage soon. I have never bought oakleaf hydrangeas mail order so I am not sure if this 4" pot was a good buy or not?!? It will develop more stems in future years. I think you will be ok though.