Unlike the previous year's calendar, which only represents one Mixel in each page and only one or two Mixels from each tribe are present in the calendar, all members from Series 1 through 3 and Series 5 tribes are present in the calendar and are represented by having one tribe for each page.
It is unknown why the Series 4 tribes aren't present, despite them being already in stores by the time of the calendar's release. As well, Series 6 is not present in the calendar, despite the fact that the characters would have been released during the year of the calendar's production (and they were already revealed at Toy Fair by that point).
Only Series 1 and Series 2 tribes have their backgrounds as their respective homelands. Series 3 and Series 5 have generic backgrounds or reuse backgrounds from other locations.
This is the only merchandise where Season 2 characters are used.