Advertising image of a pair of sleeve buttons. I’m not entirely sure what sleeve buttons were but they look much like what we now call cuff-links. Either way, this pair of of buttons could be used for vintage jewelry images or anywhere you might need a small button-sized image. The Nursery, February 1877 is where I found this illustration.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.