What's it mean when a guy is "copying" you in text?

(If you don't already know I have a back story on my other post.) Well me and this guy were texting and kept saying "ya" :so i just said "mhm" Later on he said "mhm" and "ya mhmmm" and was sorta mimicking or copying me. What does that mean?
Updates
+1 y
He kept looking at me today and school and his friend pushed him towards me.
What's it mean when a guy is "copying" you in text?
Post Opinion