Bearded girdles have very fine fractures, chips, or indentations. Sometimes, this is a result of the bruting process. Other times, it is the result of general wear and tear, or some sort of impact, after a diamond in jewelry has been worn. Minor bearding – ie, brearding that does not impact the overall sparkle and appearance of a diamond – is not considered a significant characteristic. OTOH, more severe chips or cracks, or any sort of variation in the girdle that impacts a diamond's overall appearance and/or performance, is something  one would not want (and, I would imagine that such a condition would be noted on a report).

I would kind of liken this to when a GIA report notes something like "additional clouds not shown..." meaning, the characteristic is so minor or insignificant that it does not warrant plotting on a report (an indication that it should not impact the overall clarity or beauty of the gem).

I think that I got that right... 

Really great answers guys!

in fact girdle mechanics is probably one area where advancements in cutting technology are easily seen. Today, they can really polished the tiny facets, Gödel so that is a faceted girdle. Up until probably the mid-1970s, most girdles were frosted. At that time, it was a big deal to have a faceted girdle.

When it comes to colorless diamonds, there is no doubt – faceted, or at least polished girdle is the way to go.
When it comes to fancy colors, it's a little bit more tricky.
Judging by way this diamond is cut, it was most likely cut relatively recently. Therefore, I have to believe that the choice to leave the girdle as slightly bearded, was made to assist in color retention from the rough.
It's impossible to notice this with the naked eye. By the way, you need a loupe to see it