The chest x-ray shows presence of pneumomediastinum.
There is a continuous diaphragm sign along with dirty air shadow tracking up the superior mediastinum into the neck.
The patient had further imaging in the form of a CT chest with oral contrast which ruled out esophageal perforation as the cause. Patient was admitted and discharged 48 hours later in a stable condition. A cause was not found for their pneumomediastinum.
Further reading https://pubs.rsna.org/doi/full/10.1148/radiographics.20.4.g00jl131043