Concerning the appearance of assets on screen

When I choose ,, project properties, general, sizing, responsive, the images appear in the companion on mobile so small, & when I choose fixed the images appear so big & not completed on the mobile screen, knowing that actual size is 30* 25 cm, resolution 72, how can I solve that ? Thanks.

I made screen orientation to unspecified , how do i make the block, I want image width to be as screen width in both portrait & landscape,

That sounds like Fill Parent.

But then you have to consider what to do to the image to preserve its aspect ratio.