The latest comment widget provided by WordPress is really weak. It doesn't display the commenter's avatar or the comment content, which is obviously not user-friendly. We can install the Decent Comments plugin to optimize it. You can search and install this plugin through the WordPress dashboard.

Plugin Settings

After enabling the plugin, you can see Decent Comments in the Appearance - Widgets section. Drag this widget to the sidebar to add it.

After adding the widget, you can configure Decent Comments, such as whether to display avatars, display admin comments, etc. The following image shows the configuration used on my blog, for reference only.

The default style of Decent Comments may not be compatible with your theme. The following CSS style is used on my blog, for reference only. Please adjust it according to your actual situation.

/* Latest Comments */
.decent-comments ul li{
    list-style-type:none;
    /*border-bottom: 1px solid red;*/
}
.comment-excerpt{
    margin-left:60px;
    border:1px solid #C0C0C0;
    border-radius:3px;
    background-color: #F0F0F0;
    padding:5px;
}
.comment-avatar img{
    border-radius:50%;
    margin-left:0;
    padding-left:0;
    margin-right:10px;
}
.comment-author{
    font-weight:bold;
}
.comment-excerpt{
    font-size:12px;
}

Implementation Effect

You can see the approximate effect in the "Latest Comments" toolbar on the right side of my blog.

Summary

After searching online, most methods involve modifying the WordPress code itself or creating custom widgets, but the effects are not ideal and not conducive to future maintenance. It is more practical to directly use the Decent Comments plugin.