gtk:picture-can-shrink (object)

object -- a gtk:picture widget
setting -- a boolean whether the picture can be made smaller than it contents

The accessor for the can-shrink slot gets or sets whether the picture can be made smaller than the natural size of its contents.

If set to the true value, the picture can be made smaller than its contents. The contents will then be scaled down when rendering. If you want to still force a minimum size manually, consider using the gtk:widget-size-request function. Also of note is that a similar function for growing does not exist because the grow behavior can be controlled via the halign and valign properties.