This is the DS200 digital scanner. It’s actually a very simple machine:
There is a Scanner at the top, which scans and counts each ballot.
The ballots then drop into the Ballot Compartment below.
There is also an Auxiliary Compartment on the front. If the DS200’s scanner malfunctions or jams, the Chief can unlock this compartment and voters can temporarily insert ballots here instead. At the end of the day, election officers would remove these ballots and insert them into the scanner (if it is now working) or hand-count them.