I agree with SnowyFalcon. That is N. coccinea. The one you think is highland alata is actually a hybrid called N. 'Miranda', which is most likely the cross of N. maxima x N. mixta. The plant you're looking at as a lowland alata is actually N. ventrata, the hybrid of N. alata x N. ventricosa.
The N. 'Miranda' will produce pitchers almost a foot long once the plant gets up in size. Also, as the pitcher matures, the peristome will loose the striping and turn a solid deep red.