Preview PNG export adds Color profile: sRGB IEC61966-2.1 to my image file...

Hi all so I'm a little perplexed and wondering if anyone can shed some light. I have some images I made in a content creation tool (Adobe Substance Painter) that I exported. I can right click on the BaseColor output image and click "Get Info" and I can read the following: 

Dimensions: 4096 x 4096 

Color space: RGB

Alpha Channel: No

But when I go into Preview and just re-export them in a PNG format I can right click, "Get Info" and now read: 

Dimensions: 4096 x 4096 

Color space: RGB

Color profile: sRGB IEC61966-2.1

Alpha Channel: No

There are two main differences here between the first image and the re-exported image. The first one is that the image file increased in size from 2 Mb to 2.7 Mb. The other difference is the "Color profile: sRGB IEC61966-2.1".  I understand a color profile acts kinda like a translator between an image's color space data and the display or monitor I'm viewing it on. So I see that the Preview export is embedding the image with a color profile but would that also account for the additional 0.7 Mb? Seems like quite a large size difference for it to just be a color profile that is added. Does preview also re-export a less compressed version of the image when you do a png export? Is it adding some additional metadata to the file?

Maybe I have this all confused but any insights would be greatly appreciated!