This is the ultimate question of when is it appropriate to bring personal belongings from home in to decorate your desk. The problem is - it could be too soon and you could risk looking a bit keen to have your first desk. A desk covered in plants, photos, and personalised mousemats could be a bit much. You also don't want to be the guy with the mini-heater or personal fan. Or on the other hand, you could be the one that doesn't look like he's planning on staying. Having a bare desk with nothing but your work and computer on it could give off clear signs that you can't be bothered to bring anything in for your desk as you will just have to remove it again in a few months. No one wants all this potential reputation hanging over their heads at their new job.