The mockery of United Airlines over their treatment of passenger David Dao in April 2017 (forcibly dragging him off a flight to open a seat for a United employee) manifested itself in a humorous photograph circulated online, one supposedly showing United Airlines passengers seated in an airliner cabin wearing protective crash helmets as a spoof of the airline's recent troubles:

The image depicts the helmeted passengers below the quippy caption, "On an actual @United flight today." But another Twitter user pointed out that signage in the background of the image reflects a different carrier, Condor Airlines.
A Condor spokesperson, Susanne Rihm, told us via e-mail that the people captured in the picture are not actually passengers, but rather employees of another company taking part in a safety training course held in a mockup of an airliner cabin:
The interior shown in the picture is NOT a cabin of one of our aircraft. The picture has been taken in the course of a safety training in our safety training mockup at Condor headquarters in Frankfurt, Germany.
Rihm also included a picture of the actual cabin interior for Condor's 94 aircraft:

United was subjected to heavy criticism after the footage of Dao's being dragged off of a flight circulated online. The company admitted that the flight was not overbooked, contradicting earlier statements regarding Dao's forced removal from a United Express carrier.
The union representing the company's pilots released a statement blaming the incident on a "gross excessive force by Chicago Department of Aviation personnel."