As you get leaner, smaller decreases in bodyfat have a bigger impact on your appearance. Someone who is 20+% body fat will need to lose a significant amount of weight in order for others to notice, but if you are in the 10-12% range then small changes can make a big difference.
I wouldn't say every pound is noticed, but 6 pounds at 11% bf is a significant loss. I find that I look drastically different between 180 and 190 pounds, especially in my jaw line