This would be more like reformatting. It makes sense that they used an application that allows editing by adding images, which is why we see an overlay covering up the other user's name. It appears that the same application also allows text editing. Whether they edited the text in question is a different matter, and that would require forensic analysis.

It is interesting that they pasted the info into such an application rather than used screenshots of the original. Perhaps this suggests that this conversation was taken from a database, other messages existed between these two, or taking a screenshot would risk revealing this person's identity.