In this sentence, the word "续" means life-prolonging, and when people say this they usually mean that someone was being life-prolonged to somebody instead of someone was being life-prolonged by somebody. Why?
It's a Chinese (political) joke. It has been told that a boy is killed to lengthen the former (×2) chairman, Zemin Jiang. But it's not proven to be true yet. It's alright to used chatting with people of new generations in China. And it has somehow become a meme among them.
When people say 续命、续一秒、+1s , they are also talking about that.
If we say『续』，it is only used on Jiang Zemin the Elder when we refer to one's life is lengthened. For other people, it should mean that his life time is given to the Elder.
被续 is a China internet meme.
A hasty investigation and verdict on a mysterious death of a (kid in Chongqing) had spark many speculation back in Jiang Zemin authoritarian era.
One of the ridiculous speculation/conspiracy theory is about making use of black magic to prolong(续命) the life of some prominent figure, where the kid is the "sacrificial lamb". I.e. "我想这个穿着红色衣服的男孩已经被续了."
China netizen think the conspiracy theory is damn funny :
So China Netizen keep making fun of the ridiculous 续命(prolong another life) with sarcasm, thus some come out with 续命一秒 (prolong the life by 1 second). Thus 续命一秒 become a sarcasm for some vain action.