Okay, it’ll be quick.
Chrome: version 71
HTML:
<a href=""><img src="unknown.jpg"></a>
CSS:
a {
opacity: 0.5
}
img {
display: block;
}
That’s all you need.
Obviously it is a bug. There is no way it should work like that, right? I’ve checked in the superior browser—Edge, but it looks normal there.
Funny, huh?
Remember: this is a bug. Don’t treat is as a feature (even if it could actually be helpful).