Not exactly. They are all labeled with a quarter. But the rest of them are spaced a year apart. The last bar is visually skewed because it's not consistent with the X-axis unit established by the previous bars.
No from one bar to the next for the previous years, the gap is 1 year (ie, Q4 2010, Q4 2011 -> 1 year), but from the second last bar to the last bar, the gap is 1 quarter (Q4 2011, Q1 2012 -> 1 quarter)