hi @Murakami Fumihiko 

Thank you for comment, which translates as:

“Currently there is rotation, but there is no reversal, so if you want to reverse it, you need to first reverse it with another tool and then paste it. I would like to be able to flip shapes/images on the board.”

Correct, we don’t have a flip or mirror option right now. It is a currently Wish List item, and you can vote on it here: https://community.miro.com/ideas/flip-a-shape-horizontally-mirror-feature-157

For anyone else coming across this feature, please be sure to add your vote to the Wish List post. Cheers.