Just set it up. Can you give me a small tip? What could be the reason for the banner to open small on my site on mobile compared to your demo where it takes almost the entire screen on my phone?
Yes, because you have stretched your image even more. If you will set your slider height to 150-200 on mobile, you will see the whole image. It is not a good practice to create the slider with one image and all texts added to it. It will not be responsive ready. In this situation, we suggest you to use our banners carousel WPBakery element.