It is the "mirror" effect, or when one object is reflected across a plane to create another instance of itself.

反射对称就是一种镜子效映，一个物体在平面内反射后得到另一个自已。

youdao

This is certainly true for a plane mirror but it is only approximately the case for other configurations.

对于平面镜这肯定是对的，但是对于其它形状的反射镜则情况只是近似如此。

youdao

The image formed by a plane mirror has the same size as the object. it is also equally distant from the mirror as the object.

利用平面镜观看镜像，镜像的大小与物体相同，并且两者与镜面的距离相等。

youdao

It was as if a mirror had been placed in the center of the plane to remind us all of our humanity.

FORBES: Celebrity, Inc.