  Tremendous information is hidden in the light curve of a gamma-ray burst
(GRB). Based on CGRO/BATSE data, Hakkila (2021) found a majority of GRBs can be
characterized by a smooth, single-peaked component superposed with a temporally
symmetrical residual structure, i.e., a mirror feature for the fast varying
component. In this study, we conduct a similar analysis on the same data, as
well as on Fermi/GBM data. We got a similar conclusion that most GRBs have this
symmetrical fast varying component. Further more, we chose an alternative model
to characterize the smooth component and used a three-parameter model to
identify the residual, i.e., the fast component. By choosing 226 BATSE GRBs
based on a few criteria, we checked the time symmetrical feature and time
translational feature for the fast components and found the ratio is roughly
1:1. We propose that both features could come from the structure of the ejected
shells. Future SKA might be able to observe the early radio emission from the
collision of the shells.
