This is the 2nd opening sequence for Attack on Titan.
Watch it until around timestamp
0:26Now, the important bit here is
0:19 through to
0:26Note how it is going through the entire cast of main characters. at
0:25 you see Annie turning around to face the rest of the cast head on, like she's in conflict with them.
Notice that two other characters, right before her, are beginning to turn just the same, while everyone else is looking to the left side of the screen directly. They're looking from the corner of their eyes as they turn, their motion merging into, ultimately, Annie's own turn.
I think that this is an intentional teaser. We know that Annie is the female titan and she is now in direct conflict with the cast, however the Colossal and Armored titans are not revealed, and currently not in direct contact, so they're not facing opposite/in contention with the cast yet, they're simply getting ready to turn.
An animated representation of the face-heel turn, as it were.
In short, I think Bertholdt Fubar is the Colossal Titan and Reiner Braun is the Armored Titan. Or vice versa. I'm going based on how Reiner has blond hair and the Armored Titan had white/blond hair.