It's basically 6% longer, wider, and thicker.
I like small phones. 6% doesn't seem all that different from the current SE.
The fact that all that space seems to be going to battery life does seem nice...
Well it's 11% longer, wider, and thicker than the 13 mini, which has better everything than the SE.
Those 6% increases compound together though to create something with 20% more volume, that is pretty substantial