Screw Heads

The reason why I put up with stuff like this in my other online lives, is so I can run across stuff like this:

Perplexed? Full and better details here. (And yes, I'm aware I'm a full eleven months behind the times here, so apologies of it's old news to you.)

Now aside from the artistic aspect - and personally I think the sort of 3D mosaic effect is trés cool and definitely the best use I've ever seen for that many cross-head screws, but it's a subjective thing- this brought up many questions of a woodworker's variety:

How many impact screwdrivers does he get through in a year? (This surely has to be a helluva endorsement of the Milwaukee's trigger control if he really never tweaks a screw with a regular power-less screwdriver...)

What's the ply thickness? And how often does he inadvertently screw the picture to the wall?

What's the preferred make of screw?

Has he ever considered branching out into Pozidrive, or even Robertson square heads, for variety?

How about a background made of all the empty screw boxes he must have? ('cos let's face it - telephone directory pages are a bit... grey)

How about going old school and driving all those screws with a Yankee? Or a brace?

Ever considered slotted screws and then, um... lining up all the slots...?

And finally; it'd be truly amazing if he could do it with nails...