The featured image acts a a slide background.
After testing, The height of slider depends on the elements.
For example if a slide consist of 2 column
The left column contains text and button.
The right column contains single image element 600px tall.
So the slide height is actually follow the height 600px of the single image element.
The example flower slider is taller than motorcycle slider because the image use in flower slide is taller than motorcycle slide.
Is it possible to make this 2 colomns slide in desktop also appear as 2 columns slide in mobile