So it looks like the image just gets stretched on mobile, which makes the text that appears in the image to also look stretched. There are other themes that allow you to select a different image specifically for mobile that prevents things like this from happening, but you should know that it’s not best practice to write text in an image. Search engines will not see text on images and that could hurt your ranking. My advice would be to choose a different section type such as Image with Text inside of your current theme so that you can somewhat recreate this look while also having hard coded text. Good luck!