myfoodchange.com

page title should be in the format, daisyandberries.com.au,  i.e. no http:// in front (www is fine)

then just save, view in your store, right click on the resulting thumbnail, and save it will a name in exactly this format.

e.g. for daisy-and-berries-

daisy-and-berries-website-screenshot-1024px.png

Then add the 1024 image to a blog post in shopify

the blog post