<img src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/94/MUTCD_R3-8b.svg/160px-MUTCD_R3-8b.svg.png" style="width:10%;height:10%;">
Below is a message I received from Teachable Customer Care the other day.
Thanks for reaching out to Teachable Customer Care! Great question about adding images in the lecture titles. I know how aesthetically pleasing this can be for students. I'd be happy to help.
At this time, there is no native way to add images to lecture titles. Sorry about that!
You could possibly use some custom code to insert an image