We decided to reject H0 based on P-value. But...

Hi,

I am wondering if there is a more evident way for a non-statistician person to understand why we reject the H0?
We here rejected the H0 based on comparison of P-value and the SL?
But how do we exactly see as a dummy that Mg level of difference is higher than 0? Is it the T-score (-2.29) that is lower than 0?