Image not going full screen on mobile


I would like the leaf image on this page is go full screen on mobile. I have a feeling that the problem has something to do with the aspect ratio of the image (as the other images on the same page all go full screen. How can I make the image go full screen on mobile?

Screenshot from 2021-12-16 15-19-03-min

Is there 40px padding all round on the container it is in ?

Thanks Dave. I convinced myself the problem was due to the image dimensions and so I was looking but not seeing [the padding in DevTools inspector].