Some had suggestions for what the person behind her should have done.
"I would quietly lower the tray, let her hair fall in and then close it up again," one person wrote.
"It would piss me off and I'd tell her to keep it in her seat. If she gets pissy, offer to cut it," another one said.
"I totally agree with you, absolutely unnecessary and kind of gross for that matter, how would she like it if the person behind her sneezed into her hair instead of their tissue. That might teach her," another Twitter user replied.
Others argued that it is not something worth getting angry about.
"Lol nah. If I need the tray I'd just let her know I need to get under her hair for a sec. But why would I get mad? Flight over soon, on my merry way," one person replied.
It is not known when the photo was taken nor where the flight was headed.