Even before The CW's current incarnation of superhero series went into four-way synergy mode prior to the winter hiatuses, fans had already been enjoying the network's comic book crossovers for a couple of years. And soon, the two dramas that kicked it off, The Flash and Arrow, will combine for a crossover like none you've ever seen. And it's one that you might not have seen it all if you weren't prepped for it by this story. Here's how Arrow co-creator Marc Guggenheim teased it.
Brilliant. Not only for this specific crossover itself, but the introduction of this kind of instantaneous cameo could make for some interesting advancements in the future. Basically any moment in the Arrow-verse's three Earth-1 series can now be retconned to include The Flash zipping through any scene in such a manner, perhaps in an effort to stop Iris' death. I don't necessarily expect that to happen, but I didn't see it coming when Futurama did it, either, and The Flash is way more into messing with the past than Futurama was. (Savitar has a shiny metal ass someone can kiss, too, for further needless mash-up talk.)
In any case, let's look at this specific cameo in the post. For something that's happening on Arrow, everything looks surprisingly Flash-y. For one, it's not even Star City being shown, as that appears to be Central City Police Department Chief David Singh inside of his GCPD office. So it's possible that someone from Star City's law enforcement is giving a shout out to see what's up on their end, perhaps due to a metahuman causing trouble.
Or maybe Barry and Team Arrow conspired to distract the Chief with a phone call so that Barry could zip through and do whatever it is that he needed to. It looks like The Flash is slapping the computer screen, so it could be a note for Singh to pick up milk on his way home from work. More likely, he's reading what's on the screen or taking something away from Singh's desk. In any case, one would assume that whatever Barry is doing would assist someone on Arrow proper. Since that new Black Canary recruit is from Hub City, it won't likely be that. (Or will it?)
While this upcoming Flash in the pan won't take up much of anyone's time, it's definitely not the only future crossover hitting The CW's DC Universe. Legends of Tomorrow, in particular, is set to welcome other heroes to its time-travel chicanery, and Marc Guggenheim is extremely excited about where those are going, too.