Is this something new, or seasonal? I don't recall this from my last trip to Ginkauji (maybe 10 years ago).

Any more info as to what they are (other than "art") , and how they're made. Look sorta cool...

Oh, no, you saw it, it's one of the main features of the temple. There's a huge sand cone at one end, and since it's so big, probably that's the feature you remember from the karesansui at Ginkakuji.