Unfortunately, when you post to Twitter via Instagram, the image appears like a link.
The image doesn’t show up like images uploaded to Twitter automatically.
There is a very easy hack though.
It involves using a service called IFTTT, which stands for If This, Then This. You will need an account on this service to use this hack.
I just set up a rule that says “If I post a picture to Instagram, it will a) look like it was uploaded to Twitter and b) post to Twitter automatically.”
The rule lives here: https://ifttt.com/recipes/129391
If you primarily use Instagram to post pictures — and want them to appear as native Twitter pictures, please feel free to steal my rule.
If this works, it’s a great idea. Well, it’s a great idea even if it doesn’t work. I stopped using IG a while back, but I wish everyone I followed on twitter would post their IG photos this way, so they didn’t open a new tab every time.