A report exists to answer one question: is this working
The purpose of a client report is answering whether the engagement is delivering what the client cares about, not proving that a lot of activity happened. A report full of metrics unrelated to the client’s goals reads as filler, however impressive the individual numbers look.
Tie every number back to what was promised
If the engagement was framed around growing an audience, the report should lead with follower and reach trends. If it was framed around engagement or conversions, those numbers should lead instead. A report that leads with whatever metric happens to look best that month, rather than the one the client cares about, tends to read as evasive even when nothing is being hidden.
Native, real numbers build more trust than a polished summary
A report built from each platform's own native metrics, rather than a third-party estimate, holds up better under a client's scrutiny, since they can verify the same numbers inside the platform if they want to. A number that can be independently checked is worth more than a nicer-looking one that can't be.