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In my answers to Plotting Error Bars on a Log Scale I used a so called "torn edge" effect from on one of the images. @SjoerdC.deVries commented: "BTW I liked the ripped-out look of your InputForm picture; Mathematica? It's ideal for pictures that have to convey the message "There's more of this, but that's not important". Though it was a software called Snagit, I think Mathematica can easily do it. For example, this train of thought:

Imagine you have an image which you'd like to limit with torn edge:

a = Image[Rasterize[RandomReal[1, 50], RasterSize -> 700]]

Generate random walk:

b = ListLinePlot[SeedRandom[4]; Accumulate[RandomReal[{-1, 1}, 2000]], Axes -> False, Filling -> Bottom, FillingStyle -> White, AspectRatio -> 1/13, PlotStyle -> {Thickness[0.0015], GrayLevel[.0], Opacity[.5]}, PlotRangePadding -> {0, 5, 0, 5}, ImageSize -> 1000]

Make shadow:

c = ListLinePlot[SeedRandom[4]; Accumulate[RandomReal[{-1, 1}, 2000]], Axes -> False, Filling -> Bottom, FillingStyle -> White, AspectRatio -> 1/13, PlotStyle -> {Thickness[0.005], Opacity[.3], GrayLevel[.2]}, PlotRangePadding -> {0, 5, 0, 5}, ImageSize -> 1000]

And compose everything:

d = ImageCompose[b, c, {Left, Bottom}, {Left, 5}]; e = ImageCompose[a, d, {Left, Bottom}, {Left, Bottom}]; ImageCompose[e, ImageRotate[d, Pi/2], {Right, Bottom}, {Right, Bottom}]

This kind of works - but is obviously very raw. Right bottom corner is problematic for example. So can we make it work? Some perhaps good things to think of:

Single function where we feed image and pointers which edges to torn.

All image sizes would work

All methods are good, no need to use random walks

This question maybe helpful: How can I make a 2D line plot with a drop shadow under the line?