The question Snopes was answering: "Donald Trump expressed strong opposition to the war in Iraq before it began in 2003". Snopes says this is false.

The video you linked is an excerpt from a Trump interview where he mostly waffles on whether we should attack Iraq. The closest he comes to opposing the war is saying that perhaps we shouldn't do it yet and perhaps should wait for the UN.

In what universe is that "strong" opposition?

Strong is perhaps a fuzzy term, but the context is Trump making claims like this one during one of the GOP debates: "I’m the only one on this stage that said, ‘Do not go into Iraq, do not attack Iraq.’ Nobody else on this stage said that. And I said it loud and strong".

Factually, his opposition to Iraq was not publicly strong prior to 2003. As is classic for Trump, in 20015 he claims the opposite, despite his purposeful equivocation. This is a strategy he employs to cover all his bases whenever possible.