I'm really, really old (over 50!), and to me emoji seem small compared to text of the same size. I think this is due to emoji having more detail than letters, so it takes a little more concentration to "read" them. To fix this, always draw emoji several point sizes larger than neighboring text, or allow emoji size to be set independent from text size. P.S. I've had this same complaint about every texting app, not just Textra.