Also, the second picture is a bit misleading because it compares the SE to a container that itself is larger than the mini (as you can see in the third picture).
[0] Numbers from Mactracker. SE is 4.87" x 2.31" = 11.2497"^2. Mini is 5.18" x 2.53" = 13.1054"^2. That's a 16.5% increase in surface area
* iPhone 5: 4.87 x 2.31 x 0.30
Volume: 3.37491
* iPhone 12/13 Mini: 5.18 x 2.53 x 0.29 Volume: 3.8
* iPhone 6: 5.44 x 2.64 x 0.27 Volume: 3.877632
* iPhone 8: 5.45 x 2.65 x 0.29I would argue that 9% is far from marginal.
The increase from a 12 mini to an iPhone 6 is very minor; the increase from a 6 to 8 is marginal.
From a 5 to a 6 or 12/13 mini is substantial.
The fact is the iphone mini wasn't popular despite some demand for a small phone, phones are heavier due to the evolving chip architectures plus the necessity to stretch every millimetre of screen size. Likewise for laptops (Like many I would pay over the odds for a modern Thinkpad that felt just like a x220) but in reverse, laptops get lighter and thinner with worse keyboards whilst phones get bigger and heavier.