A 2-day-old, 1.2 kg female neonate born prematurely at 28 weeks gestational age, has worsening tachypnea, intercostal retractions, and hypoxia. She is intubated after the failure of nasal continuous positive airway pressure (CPAP) and oxygen therapy. Which of the following chest x-ray findings is MOST indicative of respiratory distress syndrome (RDS) in this neonate?