You'll want to do something like this:
put the imagedata of image sheep into animalarray[1]
or this
put the text of image sheep into animalarray[1]
the imagedata is basically a bitmap (sequential sets of 4 bytes, ARGB) representing the image on screen as it appears. this property changes at the image changes, i.e. if you set the width for example, the imagedata property changes to reflect this
the text is the binary data (i.e. file) that is the 'source' of the image. this remains the same after manipulating the image object in the ide.