Date & Time: Been around for a while, but picture taken 1/10/19, like next to midnight eastern.
Frequency: Always on M Lalafell on at least DX 11 (Unsure if 9 somehow avoids this.)
World name: Adamantoise, doesn't matter.
Character name: Tiny Boy, doesn't matter.
1. Equip Whisperfine Woolen Shorts to a M Lalafell. (Unsure if other race/genders have this issue)
2. Perform certain emotes. Not all will cause it. At the very least, M Lalafell idle 5 (the last one before it goes back to the still pose) shows it consistently.
3. Check right side of model's hip, where the skin and shorts model are meant to connect.

Image: Notice how the area between skin and short are the color of the sky in the background.