From the netflix main screen go to settings. Then press reload Netflix. That will take it away. Idk how to put it there though.
They likely pressed the ASTERISK button on Roku remote while in the main browsing menu of Netflix. This will toggle ON or OFF the display of streaming information in the upper left corner of the screen while a video is playing. If you turn it on accidentally you must stop video and return to main browsing screen to press ASTERISK button and toggle it OFF. It can happen quite easily because when you do press the ASTERISK button in main browsing screen nothing appears on the screen to notify you that you have toggled it ON or OFF.