We consider a lower weight better because lighter devices are more comfortable to carry. A lower weight is also an advantage for home appliances, as it makes transportation easier, and for many other types of products.
A hot shoe can be used to attach an external flash, as well as light meters, viewfinders, rangefinders and other attachments.
Resolution is an essential indicator of a screen's image quality, representing the maximum amount of pixels that can be shown on the screen. The resolution is given as a compound value, comprised of horizontal and vertical pixels.
You can operate the device easily, by pressing the screen with your fingers.
A flash is good for low-light environments, and can sometimes be used as flashlight.
The bigger the screen size is, the better the user experience.