When I tried to click the 'Click Me' link, it downloaded the image. Why is that happening?

[GintokiDai04999]

<img src="https://cdn.pixabay.com/photo/2015/11/16/14/43/cat-1045782_640.jpg">
<nav>
<a href="https://cdn.pixabay.com/photo/2013/05/30/18/21/cat-114782_640.jpg" target="_blank"><footer>Click Me</footer></a>
</nav>
<style type="text/css">
img
{
border: 1px solid;
border-width: 12px;
width: 200px;

}
footer{
color: darkred;
font-weight: bolder;
font-family: sans-serif;
font-style: italic;
font-size: 20px;
}
</style>