You haven’t heard the last of the YotaPhone, the unusual Android handset with an e-ink display on its back. Although the smartphone has only been on the market for a few months, its manufacturer is already showing off the next generation. This second act is rounder, a bit svelter, and incrementally smarter. Though it’s clear this updated gadget isn’t quite ready for prime time, it makes the most impressive case yet for a dual-screened e-ink Android smartphone combo.