An easyJet spokesperson said the airport employee does not work for the airline.
He is believed to work for French company Samsic which is contracted by Nice Airport to provide employees who help disabled passengers, including those in wheelchairs.
The flight was delayed due to a "technical issue with the aircraft", the spokesman said.
They added: "A replacement aircraft was sourced to operate the flight and a replacement crew were sent from London Gatwick."
"We are urgently taking this up with Nice Airport and their special assistance provider Samsic who we understand the person photographed works for."
The spokesperson said passengers were given regular updates and refreshment vouchers but Mrs Ark claimed no one told them why their flight was delayed - nor when they might be able to fly home.
The airline's spokesperson said: "EasyJet is very concerned to see this picture and can confirm the person in the photo is not an easyJet member of staff nor do they work for easyJet's ground handling agents in Nice."
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