After reviewing the spec for i18n issues, I wasn't clear what the function of the 'writing-mode' and 'direction' properties was. They occur, e.g., in 8.3. Setup view transition:

Set capture’s old styles to the following:
[...]

• writing-mode
  The writing-mode of element.
• direction
  The direction of element.

And similar in 8.9. Update pseudo-element styles.

These properties are set on elements that are images. But they don't have effect on images, do they? In other words, would anything change if these properties were omitted from the style for these view-transition pseudo-elements?

If they do have an effect, a note or an example could be useful.

And, please, write the answer to this issue, and any explanation in the spec, in simple language! We (the I18N WG) found the spec rather difficult to understand…