From MozillaZine Knowledge Base
SeaMonkey allows users to see a thumbnail of the webpage open in a given tab by hovering the mouse over the tab. This preference controls how wide the preview is (the height is proportional to the browser’s height).
Possible values and their effects
A positive integer, determining the width of the tab preview in pixels. (Default is 300)
First checked in
Has an effect in
- SeaMonkey (nightly builds since 2006-06-25)