Some uploaded images displayed sideways

[TonyRippy]

The problem is described in detail here:
Ok, found the problem! A good description of what's going on can be found here:
https://www.howtogeek.com/254830/why-your-photos-dont-always-appear-correctly-rotated/

I've run 'exiftrans -a -i' on all the images uploaded to date, but we need a more bulletproof solution. A possible solution is using something like:
https://github.com/blueimp/JavaScript-Load-Image