Sorry for the long delay responding! Had to gain access to an old test machine.
I believe you'll find them under: C:\Users\[username]\AppData\LocalLow\Crafted Reveries Limited\Shu_s Garden
Assuming C: is where Windows is installed.
Also, BTW the reason it pauses for so long is that these are actually scaled up 8x. This feature was for internal screenshot-taking purposes and in retrospect should probably not have remained connected to a controller button...