While browsing the site on my Android mobile, I found that there is no option to delete comments through the mobile website.
In order to take screenshots, I recreated the issue using the mobile link found in the website footer section and rendered the mobile layout in Google Chrome browser on my desktop machine.
Here are the steps that I performed:
On the site footer section, clicked on the link mobile. Refer screenshot #1.
I navigated to one of my questions and typed in a test comment. Clicked the Add comment button to submit the comment. Refer screenshot #2. I didn't get any error message when the comment was less than the required minimum number of characters. This minimum error not appearing issue has already been reported through this post: Add comment length counter on the mobile site
I see the comment on the mobile application but there is no delete option. Refer screenshot #3.
On the mobile application's footer section, clicked on the full site link to switch to the standard website layout.
On the standard layout, I deleted the comment that I posted using the mobile layout using the delete button.
Is this by design that the comments cannot be deleted / flagged on the mobile website or is it a bug?
Screenshot #6 was added in response to comments from @M. Tibbits that flagging is not allowed on mobile. It seems flagging is allowed on questions but I didn't see any option for flagging comments.
#1: mobile link at the site footer section
#2: Add comment
#3: Comment added but no delete option
#4: Switch to full site
#5: Delete option on the full site
#6: Flagging on mobile