Each pic below shows me in the same outfit and pose, at about twenty pound intervals. Will you see a difference in yourself? I dunno. I have a hard time seeing it. But I can see it pretty plainly when I look at contrasting photos. I STRONGLY advise you to take some referance before pics!
Your milage may differ, but I bet you will see a considerable difference in yourself when you lose twenty pounds.
Two things -
1. give your skin some time to catch up with all that loss.
2. Help it along with weight training. I had a lot of saggy skin before I started weight training. I still have some (even 3 years later) but I'm a LOT more toned now. Check out the Ladies Who Lift forum stickies for a lot of great info.
Yes, 20 pounds can make a huge difference. But not when you look in the mirror. THAT is in your mind, and may be for quite some time. It takes awhile to adjust to the new body. And frankly, your mind will play tricks, because there is NO WAY, with an over 100 pound loss, that you don't look different. But you may have actually forgotten just how you DID look, or you just can't take in the changes in the mirror.
I felt the same way looking in the mirror. Hubby kept telling me how much it showed and I just couldn't see it. So he made me pose for a picture in the same pose I'd been in for another shot then showed them to me side-by-side and THEN I could see an amazing difference.
on over 100 pounds gone!! 
