olark.configure('CalloutBubble.bubble_width', integer );

Notes

Set the Attention Grabber image width in pixels.

For example:

olark.configure('CalloutBubble.bubble_width', 100 );

Results in an attention grabber with a width of 100px.

This only works if you either, have the Attention Grabber switched on in the Attention Grabber settings, or are using the API call to Enable the Attention Grabber.