Thanks guys for the help.
I posted the same question on the DALPA forum and got this answer.
"A shadow period is placed on your line as a placeholder for the OE period. The days marked shadow are where your OE may be placed and the length of the shadow period is determined from an agreement reached in the staffing grievance.
You will bid normally and any trips awarded by PBS in the shadow period will have a "snapshot" taken for pay purposes and then returned to the PBS pot to be awarded to a junior pilot. These trips will then show on your line but you do not fly them as you are not qualified (need your OE). You will either be paid for these trips or your OE--whichever is greater. A good technique is to bid so that PBS awards as many trips as possible in this shadow period. Expect a comm. piece on this soon."