Mei says nothing for most of the original series, so these specials exist just to hear her voice, watch her fail at confessing, stumble through domesticity. Fifteen seconds to three minutes per episode means there's no room for anything but the exact moment that matters: her reaching for words, missing, trying again. If you loved the original, these aren't bonus content, they're permission to stay in that quiet, aching space a little longer.
Say "I love you". Specials is a set of ten special episodes from 2013 that were released alongside the Blu-ray and DVD editions of the anime. They are romance extras tied to the main series, offered as a bonus for viewers who picked up the home video release.