The Instagram account, which posted the video with the caption: "Not only are tray tables for changing sh*tty diapers on, now you can help your kids draw all over them! It's only a $104m aircraft. NBD. #parentingfail", has received an outpouring of outraged comments.
The act was variously described as "disrespectful", "rude" and "disgusting" by shocked social media users.
Instagram user @sarahpulvere wrote: "I would never allow my kids to do that because it's disrespectful & rude. Pencils are for paper in my house, not walls or seats or floors or anything else. No doubt they're an a***hole as they're encouraging the kid to do it … I'm disgusted by this."
"I would've said something to the adult if I'd seen this … on sheer principle. Disgusting," @vari_gia wrote, while @seemeslimjen added: "Pretty much all of the obnoxious behaviours of crappy passengers on this account are infuriating for one reason: they show how *entitled* some people are."
Others insisted the airline should charge the family a hefty clean-up fee to cover the cost of removing the multi-coloured marks from the drop-down tray.
However, it's just the latest shocking incident to occur on a plane in recent months.
Back in October, a mother was savaged for letting her child use a potty in the aisle of a plane in front of passengers.
The incident, which was photographed and shared o the same Instagram account, showed the mother crouching with the toddler as the child relieved themselves.
When airline staff told the woman to use the toilets instead, she allegedly berated them, saying: "I don't give a s***."
Passenger Shaming, which also has a Facebook page and Twitter account, was founded five years ago by former flight attendant Shawn Kathleen.
The account regularly shares examples of disturbing behaviour on planes.
