Following the instructions on the Makezine site I printed out 2 small pictures on thin paper on my laser printer. You need to use a laser as this leaves the pigment on top of the paper. With an inkjet the ink will seep into the paper and the technique will not work.

I used 2 types of wood, birch ply and pine.
I cut the pictures to size, removing any excess. The wood was fairly smooth but I didn't prepare it in any way. Possibly a coat of sealer would enhancive the results.

Acrylic medium was applied thinly where the picture was to be placed. It might be neater to cut the picture to shape and then apply the medium to the picture. This would be useful for adding logos to your work for instance.

The pictures were smoothed onto the medium, face down. I used a piece of polythene to smooth out any bubbles. On these small pictures this was an easy task.

The Makezine blog suggests leaving overnight but I waited 3 hours and then wet the paper with a damp cloth to rub it off. I used a small cloth to wet and rub. The thin paper came away quite easily revealing the picture. 3 hours seemed to be OK as a drying time.

The pictures look good when wet but once they had dried they had a white feltiness from the remaining paper fibres. I tried to rub these off but this resulted in damaging the picture.

I applied a coat of Mod Podge, obtainable from hobby and craft stalls. At first I thought this was a bad move because it is semi-opaque and white.

However 30 minutes later once it had dried the pictures were clear, shiny and vibrant. A few extra coats of Mod Podge or sealant would no doubt further enhance them.

This looks like a very useful technique for transferring complex pictures onto wood that I will try incorporating into my automata.
The results on plywood and pine were equally impressive.