background and banner images not resizing on mobile view

hello kind people!

I would welcome your help.

I cannot (for mobile view) resize background images that are landscape rather than portrait layout. Please see Dr Addie page as an example - I've left the troublesome section at the top, and put my less appealing alternative below it.

If it is not possible to have this work out on mobile view, how do I have the banner/landscape layout section appear only on desktop, and the portrait layout section appear only on mobile ie hide a section in each format.

If I need to do something with CSS I am new to that so can follow step by step instructions only.

url is autismpsychology.co.uk
password Help!

Thank you very much