Yes!
Found the solution, no coding required and best of all no need to change the logo on my website.
From the home page menu choose 'Design', then 'Social Sharing'. Then drop the image you want to use here, in the box, and save.
Of course, you'll want to consider a different colour scheme for the 'social sharing' logo. If you stick with the white logo just change the background to something other than transparent or white.
Cheers!