Various icons indicating a work is "HUMAN MADE". Most include a stylized hand held up with a small spiral in the palm. A extra line in the wrist may be intended to make it so that the palm can be interpreted as a noseless face with spikey hair, viewed in profile.
https://cdn.masto.host/dicecamp/media_attachments/files/113/636/088/651/647/665/original/11ba803fac3c809c.png