If it was a good looking man filming them they would be flattered. Women take photos of people without their consent all the time. All those selfies they take in public for Instagram, there are loads of people in the background who never asked to be put on social media.
Travis appear to be support/subbing act of choice though I don't know how long that can last and imo isn't the right strategy for them. I say "strategy", I'm maybe talking here about a handful of gigs but it seems like a deliberate choice.
They were the biggest band in Britain, yes, but for only about 6 - 12 months, almost a quarter of a century ago.
they are playing the Hydro themselves this month and tickets, not that surprisingly, appear plentiful.
Chvrches appear to have maintained considerable clout on the live circuit despite not scoring a chart/radio/streaming hit for some time, and despite numerous producers being obviously brought in to help create one. A tent in the afternoon would surely be a massive step down for Lauren? She could just say no.
I’m a massive fan of festivals going for this, even if it just guarantees a new announcement for 24 days and gives me a great way to find new bands when I don’t know them