A poll from a month ago showed that people are interested in the extra functionality provided by a second screen. The vivo NEX Dual Display is the latest and, perhaps, most exciting addition to that genre. So, did vivo nail it or not? The eponymous feature comes from the pair of Super AMOLED panels - one 6.39" on the front and one 5.49" on the back. Both have 1080p resolution, but different aspect ratios (19.5:9 and 16:9, respectively). So, what can you do with the second screen? The best use case is to take selfies with the main camera - a 12MP sensor with large 1.4µm pixels and an...