Since Twitter restricted people from looking at their website, lots of people migrate to mastodon instances. The more permissive of them with open registration (like pawoo for example) are being DDosed into the ground right now.
People are having a tough time using many Lemmy communities that are essentially just lists of links to outside content, like my c/dolls and c/schooluniforms, since much of the links are dead.
Since I am a data hoarder, I of course have much of the content I would like to post saved locally - but I do not want to repost some else's work without their permission and without linking to their online presence, like many imageboards unfortunately do.
Do you think it would be okay for me to post the pictures directly to reddthat (by uploading them here), but still providing the link where the post was originally made? (that may or may not work depending on the mood of whoever feels like they have to restrict their social network)
Well as long as you give the source or even at least the artist's name for example, it should be fine. if you look at reddit for example, we don't see a lot of links to other places as pictures are often uploaded to reddit itself or imgur and then the source is noted in the title or comments.
You can still hotlink directly to the images without having to go through the twitter login for example. I think hotlinking to the source while in the "body" you also link to their twitter. That is also very much a viable option.
Then if the twitter author want to takes down the images then that is within their power.
I would approach it as you described and be open to requests from creators to remove content as those situations arise. You’ve done more than your due diligence and have made it clear that you intend to attribute credit to the creators