Averaged profiles in imosflm Gui version 1

One of the questions I had using the new and amazing imosflm 1.0 GUI for mosflm ( ipmosflm ) with ipmosflm 7.0.4 was , how do I interpret the averaged profiles the gui outputs for every batch or frame

Here is what Harry Powell said ( Nov 6th 2008)

The yellow pixels are below the background plane level - you can see from this that the tails of the spots extend outside the measurement box in most cases (the yellow pixels should be randomly distributed in the background region if this were not the case); however, the total intensity in the tails is insignificant compared to the counts in the peak region.