Forum etiquette question

I was just wondering about this: 

Is it to be used as an equivalent to 'like'? So an 'upvote' = a thumbs up? I notice that one can more unambiguously like an initial post but never subsequent ones. Not a problem if the culture of this place simply doesn't work that way. Appreciation can always be shown in a consdered reponse rather than a single click. But I just was curious.