Why Are Update Set Logs Visible Only in QA and Not in Dev?

[ChetanaP]

1. What is Update set log and when created
2. When exactly are Update Set Logs created?
3. Are they supposed to be recorded only in the instance where the changes are committed (e.g., QA)?
4. Shouldn't the logs for change creation also be visible in the Dev instance?
5. Are there any scenarios or settings that might prevent Update Set Logs from appearing in Dev?
6. Could this issue be related to a cleanup process or a misconfiguration in my Dev instance?

[Uncle Rob]

Update Set logs are created on the DESTINATION instance when you retrieve, preview and/or commit.
Did some sleeping on a better "WHY" explanation.

- Say you move from Dev to Test... the reason the logs aren't stored on Dev is that the objects might not be the same.  Like if the preview from test is saying "This object is newer on test than what you're attempting to apply", that's a truth that's only true on Test.  
- Depending on number of environments and company policy, you might source your update set multiple times from the same instance.  So I apply the XYZ update set from Dev to Test, but then I also source the update set from Dev to Train.  Having the logs moved from destination to source instance could make that relationship a lot more confusing.