Train, train, plane,
?, plane, train,
plane, train, train.
I don't know what that ? is. Zooming in doesn't help. There are train tracks at the front, but the blue parts look like some kind of container-sized temporary office space. I guess those things beyond the blue parts could be trucks, but they could be anything.
If no images contain a truck, I'm supposed to click Skip. However, clicking Skip did nothing (it's greyed-out, so that's no surprise).
Eventually, I clicked the ? and it worked. I guess there must be trucks in there somewhere, then.
Maybe I was supposed to click the one at the top with the + sign next to it.