By default every manipulation will only be applied once to your image. When calling a manipulation method multiple times only the last call will be applied when the image is saved.
##Example usage
// This will only lower the brightness by 20%
Image::load('example.jpg')
->brightness(-40)
->brightness(-20)
->save();

##The apply
method
The apply
method will apply all previous manipulations to the image before continuing with the next manipulations.
##Example usage
// This will lower the brightness by 40%, then lower it again by 20%
Image::load('example.jpg')
->brightness(-40)
->apply()
->brightness(-20)
->save();
