As designed Rotating images

[PeterUwe89]

Thx a lot! So my conclusion is:

A) Photos were uploaded externally via another host -> XenForo possibly no influence with EXIF support
B) Photos lack EXIF data (screenshot, fundamental changes, ...)
C) Photos are taken upside down and "normal orientation" stored in EXIF data is already oblique and is therefore adopted

 

[Chris D]

A) Photos were uploaded externally via another host -> XenForo possibly no influence with EXIF support

That is true, we'd have no influence over that but some browsers may attempt to use the EXIF data to orient it correctly - though they might not always get this right. That would account for the different results you reported earlier.

Most of the time it should be straight forward and things will be oriented correctly. But, yes, they are generally the things that can go wrong sometimes.