I believe these were supposed to have been distributed free with the first (10,000?) 434/504's shipped, although I only just received mine after four months of chasing.
What you actually get is a PCMCIA adaptor for CF cards and a CF card containing a collection of images of fine art and photographs. Whilst nice to demonstrate the facility, the images themselves will not be to everyone's taste.
Whilst waiting for Pioneer to ship this to me, I bought an off-the-shelf PCMCIA adapter from Jessops for the princely sum of £7.99 and have used this to show off family photos held on standard CF cards to excellent effect.
The facility is both convenient and impressive. If you did not receive the card, buying one yourself is cheap and easy.
It may be that you can acquire these separately from the plasma as it was boxed as if ready for commercial sale as a standalone item (and labelled Volume 1 implying that there may be others available for purchase separately in the future).
I should point out that whilst it took a ridiculous amount of time to receive this, Pioneer never argued about eligibility - it was (allegedly) simply a matter of supply and demand. I was also sent a complimentary pair of headphones by way of apology for the delay which was a welcome gesture.
I bought a multicard reader for mine which reads Smart media, Sony stick and Flash Media.
They all read the pictures but be careful how they are saved onto the disk as I found that fiddling with the pictures in a photo shop application the box wouldn't read them until i renamed them as proper Jpegs.