Problem with .png upload resizing to a smaller resolution

I recently uploaded a 1080p Watch_Dogs screenshot in .png format, which has never given me issues before. When trying to view it, it bugs out for a split second by showing a smaller resize of the image in the bottom right, and then resizes it making the resolution of the image much smaller. I did not do any sort of cropping during the process. It was just supposed to be a straight image upload with no modifications.

Here's the image in quesition: http://www.giantbomb.com/images/1300-2655506. It should be 1920x1080, but this is the resolution it gives me: http://static.giantbomb.com/uploads/scale_super/7/75926/2655506-watch_dogs+2014-07-10+01-27-51-01.jpg.

I tried uploading the same image again, and the same problem happened. Any idea what's causing this to happen? Thanks!

Using: Win7 x64 and Firefox 30.0

EDIT: It looks like any of the older 1080p .png images I uploaded in the past, which used to work and be represented fine, are also resizing to a smaller resolution now. This is definitely a recent bug.

We recently changed image galleries to show scaled versions of images for performance reasons. It's something we're still playing around with.

@laika: Thanks for responding. I get why you'd do that for performance reasons, though it'd be nice if maybe instead of a resolution change, a file format change was done instead. Just a thought.

I also understand .png files are normally much larger in size than a .jpg, but it's nice to be able to share raw screenshots, especially for PC games.

@laika Want to chime in again, and say I don't get these changes. Wouldn't having an image file size limitation during upload help more than using a server's processors and memory to do a resolution and file format conversion for every image as it's displayed?

My largest gripe with this is the resolution change. Also, the original image that was uploaded (let's say it's a 4mb .png) is still there in the back-end and now has to go through an extra conversion process when displayed. It slows down performance if anything.

I can understand wanting to increase performance and possibly cut down on server costs, but this doesn't seem like the way to do it. Constructive criticism here; just trying to help if possible.