Photo large view 1:1 scrolling moves the underlying page

When opening a photo in the large viewer and clicking the 1:1 option -and the image is larger than the frame- there will be scrollbars.
Using the mouse's scroll wheel (or shift+scroll wheel for horizontal) with the cursor hovering over the image however does not scroll the image, rather the forum thread behind it.

added:
On desktop you can work around this behaviour by hovering over the scroll bar while using the scroll wheel or simply click and drag.
However on mobile there are no scroll bars, which means you cannot pan around the image.

Didn't want to open a new thread for this find related to 1:1 view:

When an uploaded image is smaller than the "fit" size of the lightbox and you enable 1:1 the image is rendered twice. Once in the centre and once aligned top-left.
e.g. this image.

This website is in its infancy and is being updated and improved frequently.
The slideshow image viewer is only four days old.

I know. These are not complaints, rather reports of quirks and bugs found. Hopefully they help in the process of improving.