So I'm currently trying to review a manuscript for my labmate, who I have good working dynamics with, and I've been slowly combing through the rough draft and find that many of the bar graphs he has in the manuscript have truncated Y axes. He claims to have statistical significance between control and treated groups, yet the fold changes in several cases is quite small. The bar graphs representing these changes have truncated axes. Should I say anything about this? I feel like I'm walking on eggshells with this. There are small, but statistically significant data, that will look small if it is plotted as a fold change from 0-1 on the Y-scale. I'm going to give him the benefit of the doubt and assume it is just truncated to show that there is a change and not to mislead about how large the size of the effect is. How should a small, but apparently statistically significant fold change be represented? Should I say anything about this to him with the risk of sounding like I'm trying to undermine his work on cheap technical issues? Or should I simply privately message my PI and have him ask him about this?