Thanks for your reply.

From the beginning of my hive journey, I've learned that every images collected from online should be credited properly. I don't see you mentioned pixabay or unsplash anywhere in your post.
and about the thumbnail.
I believe you collected the image from online and then used canva to add the letterings and the arrow and if that's true then you can't say you made it.

This is what I know and I may be wrong. If you know otherwise then you may enlighten me, I'll be happy for that.