It is about telling the truth about a student’s current achievement and then, together, doing something about it, helping him or her become smarter.
This "you can get smarter" claim is my primary objection to Carol Dweck's mindset philosophy.
She has simply not proven that people get smarter when they believe they can get smarter/have a growth mindset. To do that would require before and after IQ testing on three groups of people: kids trained/encouraged to have a growth mindset, kids trained/encouraged to have a fixed mindset, and a control group with no intervention whatsoever. People would have to be matched by age, sex, SES, etc. Everyone gets the same set of daily learning materials in the same sets of schools, with members of each of the three groups divvied out evenly in each school. There would be before and after IQ testing, as well as appropriate power calculations and other statistical methods etc.
THEN and only then will we know if growth mindset makes people smarter.