For similar images with the same quality, the one with smaller file size is definitely better. Use Yahoo! Smush.it to reduce your image file size before using them in your websites. Here, I explain the capabilities, limitations and usage of Smush.it.
[ No Comments ] Posted on January 9, 2012 under Webmasters' Tools
By default, WordPress’ attachment page displays the image in medium size, where medium is defined by media settings. Use this tweak if you want the attachment page to display the image with its actual size.
[ 4 Comments ] Posted on June 9, 2010 under WordPress
The default WordPress configuration is that the image embedded on the attachment page is a link to the image file itself. Do you want to remove the hyperlink and present the image in the attachment page as a regular image?
[ 9 Comments ] Posted on June 8, 2010 under WordPress