Yeah, I don't think it's the lawn chairs that were scaring people, them being armed and dressed like guerillas (while trying to keep their license plates concealed so people can't report them) is the part that's intimidating some people.
If they wanted to "poll watch" in a "non-scary way", why aren't they just sitting in the chairs waving and being friendly to people while they "watch"?
I don't have an issue with civilians wanting to watch things, that's how a number of institutional corruptions have been exposed. But, one just needs a cell phone to do that.
Here's a good litmus test for self-deputized people who simply claim they want to "monitor" a specific situation.
If they're outfitted in such a way that would get them tackled and/or shot if they walked into a bank that had armed security, then they're not actually there to "monitor", they're there to "send a message" and to try to assert their non-existent authority and get themselves into a "give me an excuse, I dare ya" situation.
If they're the tough guys they pretend to be, they should have no problem showing their faces and keeping their weapons 100% concealed so that nobody even knew they had them. (or just leave the guns at home)
Rule of thumb for civilian firearm carrying that my CCW instructor (former Army Ranger) taught us.
"Don't put yourself in any situation with your gun, that you wouldn't be willing put yourself in without it"