You might have heard the term 'irony'.
It's a slippery concept. It roughly means 'presenting a version of reality in such a way that you undermine or contradict yourself'.
For instance, saying "Everything's great!" when everyone is homeless from a flood and standing in a line trying to get their lives back together could be ironic—or else it could be sarcastic, or delusional; it can be hard to tell.
Context and intent is key. Irony deliberately uses contrasts in content, tone, and context to highlight some gap between stated reality and actual reality.
Irony relies on a kind of emotional distance, too. The people in this photo probably don't look at the billboard and think, "Well, that's ironic."
Instead, the photographer saw the irony from a distance—the clash between the advertised experience and the lived experience—and captured the contrast at arm's length, rendering it ironic.
(But all it would take are some changes in details to create other emotions: frustration, anger, sadness, resentment, determination, and so on.)