Hey, we've worked it out, this is what my developer said to pass on to you: 

I was comparing the template settings between the homepage (which was showing the avatars fine) and the new landing page, and on the landing page there was a zero selected in the box next to where it says Yes for Display Avatar. I've removed the 0 and it's now showing for me.
Can you pass this info on to the developer as it is a setting in the plugin.

My website developer has had a look at it and we think we've worked out the google/FB logo issue, you were right, lazy loading issue.   However, this is what they said about the avatar not showing: I found something in the css on that page that is hiding the avatars (they appear when I disable them in the browser dev panel), but I don't know where it's coming from. It appears to be somewhere within the WP reviews settings, so maybe go back to them with this. I couldn't find this within the source of the homepage.
#wprev-slider-2 img.wprevpro_avatarimg {
width: 0;
height:0
}

Thank you for that, we'll do some further investigating