If you ever have sent a text/email on accident and the person took it the wrong way you know the bad feeling. Sending a mistyped word in a email can make the person think that you meant that for example. One time I was texting a friend and I mispelled the word "aren't" and accidently said "are." So they thought that I was teasing/making fun of them and they go mad. I had to fix things by retyping the sentence using the word "aren't" that time and I apologysed for the confusing.
Picture From Here: