I dug into the code, looks like it use VNRecognizeTextRequest[1] from Vision framework by Apple here [2].
And the docs says >By default, a text recognition request first locates all possible glyphs or characters in the input image, then analyzes each string.
Since the code doesn't specify any preferred languages, I think it would try to detect any languages supported by the framework.
From short googling, I found this thread [3]. Looks like the supported languages depends on the MacOS version, and it only support en, fr, it, de, es, pt, zh on Big Sur.
Not sure about the rotation though.
[1] https://developer.apple.com/documentation/vision/vnrecognize...
[2] https://github.com/schappim/macOCR/blob/master/ocr/main.swif...