Some years ago when Apple shipped then new 'Mac mini' i7; with the same physical dimensions as now.
Back then, shipping box size was 14"x9"x4". With plenty of wiggle-room & packing. Inside, was retail Apple
product box, with clear shrink-wrap. Product dimension: 7.7-inch square X 1.4-inch tall. Weight: 2.6 pounds.
• Mac mini - Technical Specifications - Apple
https://www.apple.com/mac-mini/specs/
The shipping agent do good job, no evidence of drop-kicking. This should be similar to all they ship.
Actual shape and size is still similar to those from 2014+ With 100% machined-aluminum enclosure
and M1 Apple Silicon system on chip. (Other models with 'Intel-based' Mac specs may be in stock.)
• Identify Mac mini model - Apple Support (newest spec to older spec)
https://support.apple.com/en-us/HT201894
Mac mini (M1, 2020+)
Model Identifier: Macmini9,1
Part Numbers: MGNR3xx/A, MGNT3xx/A
Tech Specs: Mac mini (M1, 2020)
User Guide: Mac mini (M1, 2020)
Mac mini (2018+) (intel-based mac)
Model Identifier: Macmini8,1
Part Numbers: MRTR2xx/A, MRTT2xx/A, MXNF2xx/A, MXNG2xx/A
Tech Specs: Mac mini (2018)
User Guide: Mac mini (2018)
Minor details in shape, weight, external packing, or specs may vary.
Estimated shipping wt, add two/three+ pounds. (FedEx/UPS)