Footer Widget does not resize image.  Image is maximum size.

CSS line 3 has height and width set to auto.  If either width or height is deleted, image will resize properly.

Honestly I personally never used widgets and did not saw anyone using that, but widget simply shows content you put there. No styling, no image sizing or resizing.

Code is very simple:
<?php osc_show_widgets('footer');?>
Styling should be made in widget or in theme style sheet.