DOF is not very apparent in this image at all. Doesn't work nearly well enough to "isolate" the ornament. Also, the harshness of the flash makes it looks like a family snapshot.
Everything in this photo is too sharp for the shallow depth of field challenge - also it is obvious that you used flash - turning off the flash, using existing light and having only the ornament sharp would have been better.
Funny... the light seems a little too harsh, you might try exploring other lighting options (desk lamps, that kind of thing) to keep from flooding the subject so much.