I'll try to explain this without illustrations.
Make a honeycomb shape with the shape tool, place it on top of the image you want cropped (make sure the honeycomb is on top of the picture layer or it wont work. To bring it to the top layer press Ctrl + Shift + ]). Also, make sure the image is grouped together so the whole thing will be cropped instead of an arm or a leg ect. Then select both layers and press Ctrl + 7 to make a clipping mask. This will crop the image you have into whatever shape you put over it. To release the clipping mask select the object and hit Ctrl + Alt + 7.
Theres also a way of doing it with something called an Opacity Mask that has more advanced features but thats a bit more complicated.