This article explains the photo in more detail: https://widerimage.reuters.com/story/taking-a-stand-in-baton-rouge

She also pissed off libs in the aftermath because she dared defy the party line:

“People saw me and kept championing the ‘peaceful protest,’ and that’s fine,” Evans said.

But she says observers began to grow skeptical of her resistance strategies as she became more outspoken politically, critiquing not only President Donald Trump, but former President Barack Obama and Democratic candidate Hillary Clinton, as well. Some people now hesitated to lend their support once her uncompromising ideas of civil rights came into view, she said.