Resizing Images via Illustrator or Photoshop

Illustrator?  Are you creating a UI in Illustrator?  Is there a "live" web page currently online?  If there is, you need to find the code or JPG size referenced in the site.  If not, just scale the image in Illustrator using the scale tool.  Ideally, you'd want to size the image(s) in Photoshop ( even if it is just a layout UI ).  Scaling up is more difficult than scaling down.  Make sure your original image has enough resolution for enlargement(s).

Long and short: This may have nothing to do with AI or PS at all. To me it looks like the web site is simply fitting the image horizonatlly into the pre-defined content box, which naturally will make it look small due to the expanded long sleeves determing this. You need to change the parameters of the web skin and/ or use a different presentation approach for the hoodie liek showing it with folded sleeves. Also note that your web server may take a few moments to refresh images and could still be displaying an outdated version from its cache, so that will need checking, too.

Mylenium