Banksy, whose identity is not publicly known, confirmed on Instagram that this latest piece was his doing.
The graffiti shows a young girl in a headscarf, stencilled onto the side of a house in the Barton Hill area of Bristol with black and white paint.
She's holding a catapult in one hand, as though she has just launched a projectile.
At the end of the catapult's trajectory is a bright red shape made of red plastic leaves and flowers.
It was spotted on Thursday morning (February 13), the day before Valentine's Day.
Banksy's street art often draws attention to social issues by adding elements of darkness to otherwise joyful scenes.
In December, the elusive artist highlighted the issue of rough sleeping with a mural showing two flying reindeer pulling a homeless man on a street-bench sleigh, in the central English city of Birmingham.