Micro-Episodes and the Theme Song
It appears that in this show, there are micro episodes, as well as full episodes.
The micro episodes focus on each characters back story, and put together, form a episode. There are five episodes out together from micros, and then Season 1 commences. Season 2 doesn't have any micro episodes.
Also, the micro episodes put together immediately start with the theme song, then starting the Breakout Part 1, there usually is a short intro, then the theme song.
In Season 2 however, there is a re-run of significant parts, then a description which takes over from the theme song. Also, depending on which Avengers are present in the episode, are there in the final theme song image.