Flickr embeds need the Jetpack plugin with the shortcode module activated.
The flickr Gallery above is embedded by pasting in the link to the page. As is the image below:
Unfortunately there is no way to adjust the size.
Block Editor Embeds
The Block editor provides a Flickr embed block, which gives a slightly larger version of the image. If you paste a flickr url into the editor it will add an embed block or you can add the flickr block in the usual way.
![](https://blogs.glowscotland.org.uk/glowblogs/public/blocks/uploads/sites/9576/2024/01/24205550/flickr-embed-800.gif)