Does Mirror screen support multi-language functionality?

No, Mirror screens do not support multi-language functionality.

The mirrored web application captures the language setting of the original web application at the time the Mirror is created. If the original application’s language changes after mirroring, these changes will not be reflected in the existing Mirror.

To change the Mirror to a different language, you need to create a new Mirror with the desired language set as the default in the original application at the time of mirroring.