The adafruit_imageload library includes a bmp directory in its source which is not included in the Adafruit_CircuitPython_Bundle releases. As a result, importing and trying to use adafruit_imageload from Adafruit_CircuitPython_Bundle results in the error:
ImportError: no module named 'adafruit_imageload.bmp'
The problem can be fixed by manually dragging the bmp directory from adafruit_imageload source to the adafruit_imageload directory in the Adafruit_CircuitPython_Bundle release. It should probably be corrected in the Adafruit_CircuitPython_Bundle release build process however.