Here is RBG walking on to the stage and sitting down and then speaking in Sept. 2018. Note her head as she walks. Even in front of an audience - her head is down as she enters.
She will lift her head somewhat (but certainly not straight) occasionally as she speaks and then it's only momentarily. I doubt that she has stood as straight as is pictured in years.
https://www.c-span.org/video/?451378-1/justice-ginsburg-discusses-politicization-nomination-confirmation-process-supreme-court