Comment avatar pictures are appearing too large

I’ve have a new issue that I can’t seem to resolve. The avatar picture/image for comments is too large and is overshadowing some of the text in the comment.

Any suggestions on how I can fix this? I’m pretty new to code so can’t come up with my own fix.

Here’s a post so you can see what I mean: https://atkmagazine.com/2013/05/06/editorial-the-question-of-yellow-fever/

Thanks!