I'm having the following problem with the images of the authors. The path that is showing is this: i0.wp.com/mancheteonline.com.br/components/com_k2/images/placeholder/user.png

What would that i0.wp.com

Could anyone help me?

thank you

That is the path of the gravatar.

K2 has integrated gravatars. For more info on gravatars please visit en.gravatar.com/.

Ok My friend, but how this change? Thank you for your attention

You're welcome,
There is a setting at the comments tab (Component params).

You have to set Enable Gravatar.com avatar lookup for non-registered commenters to no.

Wow!! It worked! Thank you!

There is the possibility of putting another image?

Yes of course,

The author avatar can be changed the same way as the category image.
You have to create a k2 folder and a placeholder subfolder in your images folder of your override.

Place your user.png there and that's it.