The browser version of Twitter finally supports 'vertical display of thumbnail images'

Twitter announced on November 11, 2021 that 'vertical display of thumbnail images on the timeline' is now available in the browser version. In the mobile version, the portrait display of thumbnail images was introduced from May 2021, but finally in the browser version, the portrait image is not cropped horizontally and is displayed vertically.

This is now available on web!

Pic looking good in the Tweet composer? That's how it will look on the timeline.

— Twitter Support (@TwitterSupport)

November 10, 2021

Twitter will now show full-sized images on web --The Verge
https://www.theverge.com/2021/11/10/22775241/twitter-web-full-sized-images-no-crop-algorithm

Previously on Twitter, when displaying a tweet with an image on the timeline, the portrait image was automatically cropped to generate a landscape thumbnail. However, it is known that there are various biases in Twitter's image clipping algorithm,and in March 2021 some users introduced a portrait display of thumbnail images on a trial basis , and from May the mobile version Applicable to all users of the Twitter app.

On the other hand, in the browser version of Twitter, portrait images continued to be displayed as horizontally long thumbnails, but from November 11th, the portrait display of thumbnail images was finally introduced in the browser version as well.

If you actually look at the timeline on the browser version of Twitter, you can see that the thumbnail image is displayed vertically even when you do not click the tweet. This is expected to reduce the chance of missing an interesting tweet because the image was cropped horizontally when looking at the timeline on a PC.

However, as with the mobile version, the aspect ratio of portrait thumbnails is limited to 3: 4, so portrait images that are longer than that are automatically cropped to 3: 4 and displayed on the timeline.