Charge 6 - Why are there four pins for charging?

[Duplicial]

Hello,

what is the purpose of the two central pins among the four pins in the charging area of the Fitbit Charge 6? The two outer ones seem to be for charging, but what are the two in the middle for?

Thank you in advance.

Moderator edit: updated subject for clarity

[KatherineNY]

@Duplicial it's also likely a contact point as you can see on the charging cable side it's in a row raised platform.  Which "inserts" into the device side indent section.  My guess.