While Athena, Bobby, and May are having a conversation about May's Therapy Session, Athena is shown pouring green beans from a blue bowl into an empty clear container twice.
When Hen is talking with Sydney about Sydney's health problems, she states that Sydney is 20 years old. Sydney couldn't possibly be 20 years old and in her first year of medical school. Medical schools require the completion of a Bachelor's Degree, which is typically 4 years. Sydney would have either graduated high school at 16 and went straight to college for her BA in order to be in medical school at 20, or more realistically, she'd be 22-24 years old.
The scar that Chimney had on his forehead (from having a piece of re-bar go through his head in the first season) has completely disappeared.