Photo quality on the picturesocial.com

Hello people, I was checking my pictures lately, and I have many accounts on the web, eg. on here, on the flickr.com and on other photography websites.
I was seeing some difference between the quality of the images.
If I can say, I would say that the pictures uploaded to my flickr.com account are much sharper and clearer than the photos on here or somewhere else.
Please guys, correct my if I am wrong and PLEASE DONT TAKE THIS REPLY WRONG, IM NOT WRITING THIS BECAUSE I WANNA COMPLAIN ABOUT THIS SITE, IM JUST THINKING IF I AM WRONG OR JUST MY EYES GONE WRONG.
I have made really good connections with people on this site, so I love it , im just asking if someone else have noticed this thing.
Thanx and I am waiting for your replies