More like the first one, though I feel like I must not be good at pressing jump for such a short time as to get a double jump that low - it feels like I'm able to make it through because I've cleared the spikes by the time I go that far up. So if it were four spikes long, I would need the super-short tap to make it.
If you said something like "beat expert without needing to use a checkpoint," that would make sense to me.