Like "white supremacy", "dog whistle" has sadly become a term that's been overused to the point of meaninglessness, but it applies here.

Firstly, how often do you see people throwing up the OK symbol in photographs? Doesn't it strike you as odd to see a group of people all flashing it together in a photo? Wouldn't you assume that this must be some kind of marker of group membership?

Secondly, the OK symbol isn't the same as the white supremacy symbol. The difference between them is quite clear. But they look similar enough that people flashing it can just about claim plausible deniability when they're called out.

You have to do some serious suspension of disbelief to accept not only that Rittenhouse met with a group of Proud Boys without knowing who they were, but also that he just so happened to pose for photos with them holding up a symbol that was clearly a white power symbol and not an OK symbol (again, glossing over the fact that to would be bizarre to hold up an OK symbol in a photo anyway).

Dog whistles are designed to fool credulous, well-intentioned people. But the symbol Rittenhouse held up wasn't ambiguous. Take a look at the photos in this article. Doesn't the "ok symbol" look a little weird? Isn't it strange that he and everybody else is doing it in every single photo? If your primary concern is the truth, you can't just take Rittenhouse at his word when he's clearly motivated to lie.