Woman Singing Alone On A Train Realizes--She's Not Alone

A video has been making the rounds of a woman who thinks she's alone on the subway so she films herself singing at the top of her lungs.  She improvises about being the only one on the train and totally hams it up and acts goofy.

But as she's leaving she notices there IS someone else in the same subway car  so she adds that detail to the song.