There is a small stain on the scroll to the left (your left) of OF in OF AMERICA on the reverse, as well as what appear in the photo to be some very light scuffs in the field around ONE. But I really like the bill! The only example I own is one I took from circulation over fifty years ago. It's pretty worn with a small piece torn off along the edge.
The green ink seems a little light. Of course it's a fantastic note I was just thinking out loud why it didn't grade higher.
@Neal nails it but also the top 2 corners look soft (slightly rounded) suggesting slight circulation. TPG notes are put up on a light box where the certifiers scrutinizes if for the most minor imperfection.