Control embedded image link

Hello,
When using an embedded link in markup such as

[![asciicast](https://asciinema.org/a/14.png)](https://asciinema.org/a/14)

Is there any way to control which timestamp the png/svg will have?

The idea is to write a tutorial, with screenshots from the recording at the relevant timestamp.

Yes. You need to open the settings page of your recording on asciinema.org (you must be logged in to do that) and there you can set “Thumbnail frame” to the desired number of seconds. The PNG image is cached for some time and it won’t react to this change immediately, but you can check the effect of this setting on SVG, just replace .png with .svg in the URL.