Big image not responsive (on iPhone 4s)

Hi, I am having the same issue discussed in the previously resolved thread where the main big image is not responsive on mobile device (iphone 4s)

I tried gouravwptech’s code as advised in that thread:

It has actually made it the correct size on the iphone 4s screen but the image is no longer displayed, just a grey background with the title in it and then the image down the page, under the contact form the image is sort of distorted like it is being dragged…

I have tried smaller (and larger) versions of the image but still the same result.

https://www.allsortsberks.co.uk

Please could you advise. Many thanks

(I am using a child of the zerif lite theme)