I think it's quite plausible... THE MTK6261D chipset is popular in "smart watch phones" so the size shouldn't be a big challenge. I can't find a Chinese one quite that small in a quick search but that may be because nobody is building phones quite this impractical to use (64x32 pixel resolution?). Talk time is often an optimistic figure
It's a smart enough campaign, I suppose, people love crazy gadgets they can show off to their friends...