The image lesson is the first lesson that asks you to do two things:
- like the image Discobot sends you
- reply with an image
If you just reply with an image, Discobot says:
Looks like you didn’t upload an image
even though the image is fine, and it’s just that you need to like the message. Probably it should either not require you to do two things in response to one message, or be clearer that you have to like it, or just actually tell you that you need to like it if you reply without having done so.
(Someone else already reported this here, but apparently it’s not reproducible – initially, I dragged the image Discobot sends you into the reply box; once I failed it once, I copied the link Discobot sends you, and both times I just got “Looks like you didn’t upload an image”, not anything about needing to like the message.)