After some trial and error... and aboutl 30 feet of print failures, I've been able to incorporate the escpos-image library so that I'm able to print images embedded into messages.

Had to make some modifications to the library to support resizing, rotation and formatting but initial results are looking great.

At this point, Tilly is able to;

• Print simple text messages
• Print multi-media messages
  • GIF's take the first frame
  • JPG/PNG are printed properly
  • Resizes to 360px wide (Up/Down as required)

Can't yet print emoji, and will probably be a long-time before thats possible as all text would need to be 'rendered' onto a bitmap rather than as ascii text over serial.

Attachment's can't be printed yet either as Slack puts them in a strange place (Not on a channel technically...) so more work required there.