This is a common effect of intentional die abrasion ("die polishing"). As the relief of the letter gets lower (as a result of the field portion of the die being abraded), the letter also gets smaller. This is because the letter tapers slightly in vertical cross-section.
hey jess. I see what your talkin about and i rechecked the coin. I cant see on the coin what we see on the pic. maybe with a better magnifier but i cant see the other (Y).