I tried this a few times, and my results have been mundane, normal objects. (Perhaps it was what I expected.) Anyway, here is a list of the few times I have tried this and what I have found:
1st time: I pulled out some coins and keys from my left pant pocket, and my wallet from my right one. The coins were odd of course and had strange dates on them like 999, or 1596.
2nd time: I wasn't wearing any pants!

3rd time: I had some pajamas on, but there were no pockets.
4th time: (I was sitting and writing a recipe in my lucid dream because I was hungry and was thinking about what I would eat after a woke up. I finally snapped out of it and thought to myself, what should I do in this lucid dream and remembered the pants experiment.) The first thing I pulled out was a mechanical pencil like the one I had just been using. Coincidence? I think not. I decided to keep reaching in and pulling things out, never considering them empty. I pulled out a hand full of clear-plastic candy wrappers like ones used for mints. I pulled out a pair of sunglasses, (although they didn't feel like them when I touched them in my pocket, they were indeed sunglasses when I looked at them). I also saw a pair of regular glasses in the ever-growing pile of junk I was pulling out and assumed they must have slipped out with the other pair. After more candy wrappers, coins, keys, wallet, I was left with little balls of rolled up gum wrappers. I was going to invert the pocket to let it all fall out, but the dream ended. (All those things I have had in my pocket at least once in my life, so I wonder if that is the only meaning.)
5th time (latest so far): I pulled out two quarters and a dime. When I looked at the coins the quarters were very large like an American silver dollar in size, and the dime was normal. And that was it.
This is easy to try when you are lucid, and only takes a moment and you can still do other things in your lucid dream as well. You don't have to devote a whole dream to it. I keep finding the same old mundane things, but everybody will have their own experience and it's so easy it's worth a try. But I wonder.... WHAT'S IN YOUR POCKET?