This is a Mosaic I put together as a Birthday present. It must be said that I did not take the main photo, or indeed any of the photos that went into producing it.
This was, far and away, the most complex Mosaic I have ever attempted. I spent several days working on it and eventually achieved a usable result using 9825 cels (131 x 75). The print ended up being more than a metre tall, with each individual image still being very clear from close-up.
I was very happy with the way that certain details were retained in the final Mosaic, such as the spines of the books on the back wall, or the bottle of wine in the right corner.