I'd like to see a photo of an iPad mini and this 6.7" phone side by side.
I don't have the photo you want, but if we divide the resolution by the pixel density we get the size:
iPad mini 7.9":
2048 by 1536 pixels, divided by 326 pixels per inch (ppi) =
= 6.28 in by 4.71 in = 29.58 in^2
iPhone 12 Pro Max 6.7":
2778 by 1284 pixels, divided by 458 pixels per inch (ppi) =
= 6.07 in by 2.80 in = 17.00 in^2
29.58 / 17.00 = 1.74
So the iPad mini has 74% more display area (and if we take the iPhone's notch into account, it's more than +74%).
And of course the iPad mini's 4:3 aspect ratio is better for productivity.
But if we want to watch a 16:9 video/movie*:
- iPad mini: we keep the width (6.28 in) and calculate the height = 6.28 in * 9 / 16 = 3.53 in
- iPhone 12 Pro Max: we keep the height (2.80 in) and calculate the width = 2.80 in * 16 / 9 = 4.98 in
So a 16:9 video/movie will have:
- iPad mini: 6.28 in by 3.53 in = 22.17 in^2
- iPhone 12 Pro Max: 4.98 in by 2.80 in = 13.94 in^2
22.17 / 13.94 = 1.59
So the 16:9 video/movie will be 59% bigger on the iPad mini.
*the black bars on the iPad mini will be on the height, while on the iPhone 12 Pro Max will be on the width.