In this first short we have Joker, fresh from his imprisonment into Arkham Asylum and we have Dr. Harleen Quinzel, the new girl who replaced Dr. Crane. That's the back story we're given anyway. I sort of like how they tie in Harley's sudden appearance into the Dark Knight universe, it explains why she wouldn't have been seen or referenced previously by using the explained disappearance of an established character. The short chronicles a series of non consecutive therapy sessions between Harley and Joker culminating with Harley falling in love with Joker. There's a subtle, at least I found it subtle, manipulation in how he talks to Harley. The short is only 14 minutes long so they move kind of fast so it may seem by what's on film to be blunt, the subtext of what's happening in the sessions we aren't seeing is how I choose to interpret it. We understand that the sessions we see take place over several weeks and if what we have seen is any example we know that he's been doing this the whole time. Slowly poking at her personality, finding the chinks and sore spots, trying to see how far he can take her.
He immediately identifies her as someone like himself, he clarifies that while she is like him he's a "chapter ahead", so he establishes that not only does he understand her like no one else he knows more and can be a possible mentor in discovering this new part of herself. Her reaction pretty much confirms his suspicions giving him a way to connect and manipulate her further.
The director of this short is Kim Santiago who you may remember from the Elektra short as the titular Elektra as well as Typhoid Mary in Punisher ' and she does a good job. I don't know how much input Chris had in the cinematography but with the direct POV shots on Johanna and low angles used on Chris we establish Harley's vulnerability and Joker's imposing presence. The soundtrack is more atmospheric adding to the tension of these two characters interacting with a good ending song to add that final exclamation point after Harley finally gives in.
Both actors do a really great job in their roles but here things are, I don't know, new, maybe. Chris does a much better job as Joker in later roles when he really get's a hold of the character and makes it his own and Johanna really shines as Harley Quinn when she is no longer restricted by the role of boring Harleen Quinzel. It's a good beginning, there are some rough patches in the acting but it's worth seeing because the whole series is worth seeing and this helps to add context that series.