All of your anchor tags have a dotted underline in the following file:
https://mockutv.com/blog/wp-content/themes/seashore/style.css
In order to remove this effect from just your images, you either need to add an inline style to each anchor tag that contains an image, like so:
<img src=””>
or add this to each anchor tag that wraps an image:
class=”img”
and then add this to your style.css file:
a.img:link, a.img:visited {
text-decoration:none;
border:none;
}