I see a lot of posts where a pixiv image URL is in the source field. Are those uploaded directly from Pixiv? Whenever I try this, I get an error, presumably because pixiv returns 403 without the correct referrer header.

So do people just paste the URL afterwards or is there a trick? Also, since one can't simply open the pic from the URL, wouldn't it be better to paste the URL of the page showing the pic instead?