As big/small as a mobile phone should be, with all the good build and technology of its overcompensating brethren.
The best thing about this product is the "Mini" part. It has all the advantages and quality (screen, camera, processing, form) of any iPhone but in a size factor that reminds you that if you see some Millenial mocking a Boomer with their iPad Mini, note that they're carrying around an iPhone Maxi Pad in their pocket that they still don't think is big enough (main feature expected of iPhone 16... bigger, for some reason). Screen real estate on a computer or laptop or TV monitor is great, even a tablet or hybrid tablet device. Now you've got a phone that is getting about as easy to carry-everywhere as an early 90's Motorola brick. Get a Mini iPhone like this, else your FOMO size-overcompensation is gonna give you early-30's sciatica and something for the next generation to laugh at you about.