The output product of sen2cor

Optical Toolbox sen2cor
#1

I used the sen2cor to process the L1C product. Before processing, the extent of the image was shown as follws:

initial extent.jpg1154×813 149 KB

However, after the sen2cor processing, the extent of the output product was as follows:
after sen2cor processing.jpg1157×813 25 KB

I wanna know why? How could I solve this problem? Thanks! Any reply will be appreciated.