Why are all passport pages requested for a DTV application at HCMC or Hanoi?

For those of you who have been asked to show all the pages of your passport for the DTV at HCMC or Hanoi, is this because you have ticket yes for “have you applied for a visa in Thailand before” and “have you visited Thailand before”?

Second part of this is have any of you applied via the workcation route and been on ED visas prior to this when sending this to the embassy, for example ED visa ending/cancelled and then going that route?

Wondering if that’s an issue.

Thanks in advance and I’m sure I’m asking on behalf of many in this group.