This is pretty low-fi but it works.
You need to have viu or chafa installed - and that can be a project itself 
In high quality mode on chafa or with viu, Windows Terminal is superior to MacOS terminal because it supports many more colours (thanks Microsoft!)
Release Notes: Image Rendering (in the terminal!)
Image Rendering
- Added inline post image previews with backend selection:
- auto tries chafa first, then viu.
- TERMCOURSE_CHAFA_MODE=stable|quality
- stable: conservative output for terminal stability.
- quality: higher-detail/color symbol rendering.
- Added preview height control:
- TERMCOURSE_IMAGE_LINES (default: 14)
- Applies to preview line height; useful for tuning visual density.
- Improved viu aspect behavior:
- Switched to line-targeted rendering (-h) to preserve aspect ratio better.
- Added preview quality filter controls:
- TERMCOURSE_IMAGE_QUALITY_FILTER=1 filters noisy block-only previews.
- Set to 0 to always show renderer output.
- Added image download safety limit:
- TERMCOURSE_IMAGE_MAX_BYTES (default: 5242880)
- Prevents oversized image downloads from impacting performance.
- Added support for Discourse upload://… image links:
- Automatically resolves to /uploads/short-url/…
- Improved terminal sanitization/stability:
- Keeps valid SGR color codes where needed.
- Strips destabilizing control/graphics sequences.
- Prevents ANSI escape fragments from being displayed as raw text.