Yes, it has do to with two elliptical orbits (Mars and Earth both), and the time it takes each planet to make a full circuit.

Opposition is the condition when the 'target' planet and the Sun are precisely 180 degrees apart as seen from Earth -- same thing, different perspective: a line drawn through the centers of the Sun and the target planet also passes through Earth's center. It can occur at any point in the orbits of Earth and the target.

Have a look at this.

[If that doesn't work, go to JPL's Solar System Simulator, and (from the pulldown menus) tell it you want to show you the Solar System from above, with a 2-degree field of view, and to display orbits. Unfortunately, the results aren't an image I can post here directly.]

Remembering that, seen from the north, the planets orbit counterclockwise, it's easy to see that, as of today, Earth is still approaching the Sun-Mars line, at the same time that Mars' orbit is taking it farther from both Earth and the Sun.

Yet another way to look at it is from Mars. From there, Earth is an inferior planet. Its behavior will be like Mercury and Venus: Earth will be either a morning or evening "star", with a maximum elongation (angular distance east or west from the Sun) and apparent "retrograde" motion, approximately half the time. Earth will go into conjunction with the Sun twice in its orbit: once passing behind the Sun, and once passing between Mars and Sol. That second case is the same event as Mars being "in opposition" as seen from Earth.

And, because a Terran year is half as long as a Martian year, there will be two of those events, on average, in each Martian year.