The purpose would be to see if it's possible? If it is possible, then it would also implicate a bunch of other really interesting things. It would be very interesting to know how they are remembered by different people as well. Are the numbers read from the mental photographs or do the numbers pop into the head one by one or something else.
To me it would seem that Daniel Tammet's own personal way of seeing numbers 1-10000 as individual shapes is a result of intuitive practice and photoreaders would hardly experience exactly similar phenomenon.
If remembering Pi decimals by photoreading is clearly not possible, that would be interesting as well (or rather the question why it is not possible).
