In that case, we could imagine that the central star (presumably holding the disk together) could clear out a region near the center, and light passing through that hole could account for the brightening. I wrote a simple computer program (QuickBASIC on an IBM PC!) to calculate the light curve in this model, and we were able to get an extremely good fit to the data.
But technology has advanced quite a bit since my student years. Nowadays, we don’t need to puzzle out the meaning of a light curve and come up with an elaborate story involving tilted disks; we can just take pictures of the thing.