"Not sure" is effectively a noop bypass. It marks it as reviewed, by you, but does not remove it from the overall review queueueueueue. The "Do Not Close" one is more interesting. Based on my testing it doesn't change the overall close votes count. I imagine that it will lower it's queueueueue priority so that it shows up further down the list.

"Not sure" is effectively a noop bypass. It marks it as reviewed, by you, but does not remove it from the overall review queueueueueueueueueue. The "Do Not Close" one is more interesting. Based on my testing it doesn't change the overall close votes count. I imagine that it will lower its queueueueueueueueueue priority so that it shows up further down the list.