Is it good practice to replace external links by inline resources?

Question

In SO, the usage (or what I though the usage is since the great cleanup campaign last year) concerning the linking of external resources is that it is a bad pratice, as linking to an external resource like a blog post or a pastebin as an answer may later lead to a 404 and makes the question/answer less readable (if not unreadable at all) in the first sight.

Thus it is better for answers to add a little extract of the external resource or to post the source code in extenso if it is not several pages longs, or a reduced Short, Self Contained, Correct (Compilable), Example.

What is the consensus concerning images? An edit suggestion I made to replace an imageshack external link by the same image inlined was just rejected.

Answer 1

You were unlucky, the author of the answer was editing the post at the same time, and your edits conflicted. When that happens, the suggested edit "loses" and appears as rejected by Community ♦.

That said, your edit, albeit helpful, was a bit minor. Suggested edits are generally expected to substantially improve a post, and adding the image inline wasn't really necessary in the specific answer. It wasn't a bad edit, and I would have probably accepted it if I had seen it, but I would like to encourage you to focus on editing posts that are in need of more substantial edits.