The rule is, according to the Hatch Act, it’s against the law for someone in a government uniform to partake in political behavior. Essentially, that’s exactly what seems to have happened in an ad for Councilman Jack Evans, which features the councilman in a photo op with Chief Lanier. If the photo was staged by Evans with Lanier’s permission for use in his campaign, it’s likely a violation of the Hatch Act.
Looks like her detractors reaching pretty far to try to manufacture a problem. She’s within her rights to engage in partisan political activity as a private citizen, so the only issue is her being in uniform. Since it was him using that picture and not her the only question is was the photograph taken at a political event, since the prohibition is against someone engaging “in political activity while wearing an official uniform.”
The other issue, as I understand it, is that it was taken in his office, which would also violate the Hatch Act. A reach, to be sure, but a weird one.
The description of the photo sounds like any number of other grip’n’grin photos taken in an official capacity. I’m unconvinced.