It’s a space issue
It can be very tricky for people who live in apartment buildings to get their parcels delivered when they’re not there to sign for them. Often, there are only very small cubbyholes for their letters and goods, and if the parcel is bigger than the space, it can cause problems.
We just hope that the contents of the box didn’t actually get bent and damaged in transit. That’s not a fun thing to see when you open your mail shoot.