gifts for bosses?

So we have this tradition every year in my library that they give the director a big gift. I don't really get it. She usually gives us like tiny gifts which I would rather do without. Yet we are expected to give the manager like 20 bucks to buy a bigger gift for the director. It must be nice that someone buys you an ipod (1st year I was here) or a $200 macy's gift card yearly because you know she needs new work clothes. I mean really she makes more than the rest of us. I need new work clothes too but I have to stop myself from purchasing because I'm saving money to buy a house. Um she's not really that great of a boss. In fact, she's mean and part of the reason I work my own job plus spend over four hours a week helping out reference when I'm swamped.  And much of my source of stress. Take for instance yesterday, everyone else was gone for the day. I needed to leave 15 minutes early just because. Well, because, I was planning on working on part of what I was doing at home and because I worked through lunch. Plus, I'm salaried and work weekends and nights more often than I care to, but I leave early and get an email from her saying can I email some article to a partner. So instead of replying on my blackberry, I have to hurry home, log in to my laptop making it look like I'm still at the office to send this article and then not even get a thanks from anyone involved. Yeah that was nice. Plus you stressed me out so much I didn't go to the gym then freaked out at my husband about the house.
So why is it I'm giving her a gift? That 20 bucks could be better spent on many happier things for me.