This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.
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Divide the grid into "rooms" along grid lines so that each room is 180° rotationally symmetrical and contains exactly one white or black circle, located in its centre. In the end, shade all rooms with a black circle in them to form a picture.
Paraphrased from original rules on Nikoli
Sorry for the formatting; I can try to clean it up and provide steps with a bit more time if desired.
At the very least, I'll point out the main "hurdle" point I faced. After initial markings, focus on the marked cell:
The wall blocks most points from being centers for regions containing the starred cell.
I solved the problem using the UI which Jeremy Dover linked to in the comments.
In my case, the main hurdle was when I got to this point:
I kept on staring at the cell highlighted in yellow, and I could not figure out a way to make a symmetrical room that includes it and has a star in the center.
Eventually, I realized that the only possibility is a shape that reaches all the way to the top of the grid.
After I filled that in, everything else eventually fell into place.
This is what the solved puzzle looks like:
