Removing Large/Small Gravatars

I currently have the website https://tap-repeatedly.com/ which is undergoing something of a face lift. I have recently just changed to the “Luxury” theme, and was wanting it so only a Large Gravatar is displayed in posts, while a miniature image of the Gravatar is shown next to latest comments (if you visit the site you will see what I mean).

Do anyone know a solution, as it seems if I keep the large Gravatar, the small Gravatar vanishes..

Thank you!