It's reproducible on desktop too - exact steps are:
Create a new topic
Enter the title
Do not go near the editor field itself
Attach an image - do not click the attachment to add it to the editor field
Click 'Submit'
As nothing has been manually added to the editor field, the code to check the editor field doesn't run as there is nothing to check in there...it's empty until someone adds something, which is when the code runs. The image is never added to the editor - it's added AFTER submission, in the back-end.
Probably an easy resolution - disable the 'Submit' button at the start of the process (of creating a post), instead of after the editor field has had something entered into it.
Will take a closer look over the weekend - any other bugs, anyone? Now is the time to report them as a v2.0.4 is on the way.
Got a few minutes at the end of work to take a look- it's done, v2.0.4 submitted for approval. Other bug fixes can wait.