Shopify - change product previews from cropped thumbail

Hi,

I am seeking a Shopify expert to make two simple amendments for my website:

1. Change product preview from a cropped thumbnail, to show the whole product
2. Add a 'vegan' logo on the home page and other Category pages

See attached a couple of slides which show these two elements we need support with.

We use a theme called 'chair v1-2'. I cannot see how to do these two things from the customisable dashboard, so wonder whether it needs the code to be edited?!