According to this more recent reply, there is via manual import, but I tried to do it, and I couldn’t.
But the Knowledge guide provided by LingQ seems to indicate that they don’t have this feature anymore.
So maybe my idea won’t work since LingQ might not have that functionality?
Notes:
- This post says they don’t, and just to include the URL in the notes section.
- This post also says there is a way to add images.
- This reply has directions for adding images. But again, I can’t seem to recreate what is being described here. I don’t see an “add image paragraph” button anywhere, either.
I mainly see a lot of people requesting to use photos as hints (which is kind of a cool idea, too), other image related topics, and a mention that people don’t technically have a learning style (i.e., Visual vs Kinesthetic, etc.).
Note: I’ll update this reply if I can find more information.
P.S. Maybe I should just be satisfied with including URLs in the lesson and notes sections of sentences, and having another window open for images, 
Edit: P.P.S. I [put] in a request to have them add manual image import to the import options, but unless it has support for multiple images, it would be pretty tedious to import a single image as a lesson for a comic/webtoon/etc, but it doesn’t hurt to try 