p.s. A number of people asking if there's a lightweight version of Mastodon's web interface to use on older devices, you could try "Brutaldon":
It works on text browsers, so it may be lightweight enough for some older devices that can't cope with the official web interface.
@FediTips or just use tui/console client and cp paste puburl of post with added /embed switch... (still wonders why instances by default not redirect non js clients to text version of posts even if all post content is included in source of "To use the Mastodon web application, please enable JavaScript. Alternatively, try one of the native apps for Mastodon for your platform." error message page)