Photos no longer rotating after transfer

I transferred photos from one iPhone 4 to another, and now the receiving iPhone is no longer rotating the photos when you turn to landscape orientation. Websites do not, either. Since there is no setting for this behavior (I don't think?) and it was working before, I am thinking something was triggered by the transfer.

Do you think that is possible? What might I have done to cause it, and how can I UNcause it? :-) Thanks very much.