This woman is Lyubov Sobol, a close ally of the prominent Russian opposition politician Alexei Navalny.
She's in a car with one of his lawyers. Outside police are waiting to arrest her.
Sobol is one of several people close to Navalny that have now been detained, for promoting illegal mass protests planned for this weekend - demanding Navalny be freed from prison.
In the video she says she "has nothing to hide," and she'll go to the protests anyway.
Sobol was later released but not all of them were.
Reuters has also learned that Navalny knew he would probably be jailed when he returned to Russia from Germany last Sunday, where he'd been recovering from the incident the West says was an attempted poisoning with a chemical weapon.
At the time Navalny said he didn't believe he'd be arrested but the protests, according to one Navalny associate, were planned in anticipation of that scenario - as a way to force the Kremlin's hand for his eventual release.
He is accused of breaking the terms of a separate jail sentence, accusations of embezzlement - charges he says were trumped up.
It's not clear how successful the protest strategy may be. Seven years ago Navalny was released from prison on parole after mass protests.
But two sources close to the Kremlin say this time will probably be different.
Navalny has become more of a threat, they say.
They don't believe he's a serious threat to President Putin yet - whose approval ratings dwarf Navalny - but the sources also say that the heavy handed way Navalny's return was dealt with was likely boosting his support, and could risk turning him into a martyr.
One said he might be kept behind bars until after September's parliament elections.