The loops of the S look filled, which is not at all uncommon. Consider the miniscule size of those loops on the die, compared to the 150-ton striking pressure, and you can understand how they might wear prematurely. 
The image is nice, but a tad small to be making positive conclusions about variety. Unfortunately, many of the 1881-S varieties are difficult to attribute without great magnification.
The image is nice, but a tad small to be making positive conclusions about variety. Unfortunately, many of the 1881-S varieties are difficult to attribute without great magnification.



























