Why there's white space between an img and figcaption inside figure?
margin and padding of both img and figcaption are 0.

```css
img {
  width: 200px;
}

figcaption {
  background-color: hsla(0, 0%, 0%, .5);
}
```

```html
<figure>
  <img src="https://www.gravatar.com/avatar/61af86922698a8cd422f77ae2343d2a5?s=48&d=identicon&r=PG&f=1" />
  <figcaption>Hello</figcaption>
</figure>
```

(I'm not asking how to remove this space, I'm asking why it's there.)