One photo much sharper than the other

[Ben-Zion Herszfang]

I'm attaching two photos of the same cat, taken a day apart, with the same iPhone 7 at the same spot with the same light sources.
Why is one much sharper than the other? Is it just the focus?

 

[Just_Me_D]

Probably. Either that or the angle in which the photo was taken. One's in portrait mode and the other's in landscape.

 

[Ben-Zion Herszfang]

Thanks!
But why should the angle (portrait vs. landscape) make a difference?