landscape / portrait image display issue in "Yours" feed

[+Pontiac_CZ]

I've discovered an image display issue in "Yours" latest activity feed. Only occurs when I have both landscape and portrait-oriented images attached to a log. The issue affects the landscape image width depending on which image I open first:

1. when I first click the landscape-oriented image, it displays in its expected size. I can then switch to the portrait one using keyboard arrows / mouse and back. They both are of the same size (just 90° rotated). No problem here.
2. but when I first open the portrait-oriented image and THEN switch to the landscape one, the latter keeps the width of the former (hence appears smaller).