To created this Negative effect we of course need the picture of a negative. Lets create a document that is twice the size of our film strip and fill it white. We need plenty of room to work and we can crop later. If you are using my image, your document should be 650x650 more or less. After you created the document, open the film strip and using the Move Tool drag it into your document.

Duplicate layer Layer-Duplicate Layer and then click on Edit-Transform-Flip Horizontal. If you were able to see the layers side by side, this is what you would get.

Now we click on Filter-Distort-Shear. This is the place where you get to select the curvature of your strip. Just click on the places where you want the curves to be and an anchor point will appear and the straight line you had at the beginning will change. If you do not like what you see, cancel and do it again. Once you get the perfect curves, click OK.

Once you click OK. you will get something like this. Now go to the layer that has the other negative and repeat the process but do not change anything.

Now the two layers have the same shape.

Click on Edit-Transform-Rotate 90 CW to the two layers that have a negative in them and then using the Move Tool place one on top of the other.

Now reduce the opacity on the layer that is placed at the bottom until you get the desired reflection and you are done.

Now select the Crop Tool and draw a rectangle around your drawing and then right-click inside and select crop.

And this is it.