Poll watcher interference is a topic near to my heart, but this advice is not universal, and taking a picture inside a polling location may even be illegal.

As Voter Intimidation Efforts Ramp Up, a 2016 ‘Poll Watcher’ Meme...

There is new context around a meme that originally circulated ahead of the 2016 general election, concerning voter intimidation and "poll watchers."

Also, ask the election staff for the "Chief Judge" or whatever term your locale uses for the on-site "Election-Worker-in-Charge."