Leaving out some key statistics
Sometimes it can be tempting to leave out a key financial metric, because it does not look very good. So instead of "revenues", we show "bookings adjusted for inflation, excluding south east Asia and before sales commissions", which go through the roof in terms of growth.
Someone who sees the chart will immediately turn suspicious and ask "what about revenues?" If you are there in the room, you can explain things, if the person is reading the chart as part of cold email, you probably won't have the opportunity to recover your credibility and integrity.
If you show financials, you have to show them properly. If there is a need to explain things, do it transparently. The alternative, leave them out in your first deck and save them for meeting #2.