Newbie question about flag voting

I have flagged several covers as inapplicable to a work lately, but didn't realize that I needed to vote on my own flag. So I went back to a few to vote, and clicked yes, thinking "Yes, I agree with this flag". But is a yes vote actually a "yes, I think this is a correct cover"? I'm confused.

Inapplicable to this work: YES = this is a valid book cover, but does not belong to the particular work it's listed under. NO = this cover does belong to this work.

Spam: YES = this image is spam. NO = this image is not spam. (Note: there is a high threshold for something being spam, so this is a rare cover flag.)

Not a cover: YES = this is not a cover. NO = this is a cover (regardless of whether or not the cover is applicable to the work).

Thank you!