These CXRs are nice examples of pseudopneumoperitoneum. Chilaiditi sign is also present, i.e. interposition of colon between the liver and the diaphragm. It is only called Chilaiditi syndrome if the patient is symptomatic due to the interposing colon. 

This does not represent the continuous diaphragm sign as:

1. the diaphragmatic contour is too thick to be diaphragm alone, rather it is due to bowel wall apposing the diaphragm 
2. haustra are seen crossing the subdiaphragmatic gas, indicating it is large bowel
3. no change from two years earlier