No, it is relevant, because:
What prosecutors? This is a civil case. It’s her attorneys bringing the case. If she didn’t feel threatened, presumably she would not have.
The important question is whether merely “intimidating” a Black person with racist imagery can reasonably be considered a threat of violence by that Black person, given the history of racial violence in the US (the answer is “Yes”) Or, what puzzlegal said:
There’s your mens rea. Not actual intention to commit violence, but actual intention to create the perception of such.