Instagram has not turned back on its support for Twitter Cards, as was speculated Friday when some users began seeing full Instagram images in tweets again, despite Instagram's announcement on Wednesday it was pulling support for the feature. Facebook, Instagram's parent company, told TPM on Friday that Instagram images that can be seen in full on Twitter on Friday are just holdovers. Instagram is still going forward with its plans to pull photos from Twitter. Here's Facebook's statement in full:
As Kevin mentioned at Le Web, Instagram is dropping support for Twitter cards. What you are seeing now may be some sort of regression depending on the mobile client, but we're checking in with the engineers.