Images squashed on mobile version of site.

Hello, I realise this topic has come up before but the answers either didn’t make sense to me or were too specific (coding related to the poster’s site) and the threads are now closed for new comments.

I have an activity website that relies on pictures to demonstrate the instructions. On a PC the images are fine but on the mobile site all landscape images appear squashed horizontally, distorting the image.

I’m pretty new to website building so if there’s an easy fix or something that doesn’t involve much coding that’d be really great!

I’m using the theme “Hotel Booking”. When I add a picture to the site I upload it via the ‘media centre’ then resize it using the resize tool on the ‘edit block’ pane.

The link is for one of the pages where this issue can be seen but it’s a site-wide problem.

Thank you!

The page I need help with: [log in to see the link]