Add alt. If no option to write alt in the element then add custom attributes. Custom Attributes – Bricks Academy (bricksbuilder.io)
Attribute Name: alt
Attribute Value: Share our page on Facebook
Make a habit to write alt text for every image link.
I know this is old, but I didn’t find any other solution to this. The solution listed doesn’t work using the Social Sharing element, since it does not allow you to add attributes to each sharing icon, only to the parent list tag. The only way I was able to fix this was to use a row of icon elements instead and to write a php function to return the correct sharing url for each social network. What I really ended up doing was coding the whole thing by hand since if you want to do it the right way, you should be using a Facebook App ID and it doesn’t appear the social sharing link does and I wanted to use javascript to popup the sharing dialog in a new window.
Just inspect and take the links form social share elements and create your own social share icon list.