What determines which document in a Group appears on the Group's icon?

[DashingDave]

I can’t figure out how DEVONthink is selecting which document’s thumbnail appears on top of the generic blue “Group” icon in a database window. The first screenshot presents one of my databases: it contains 12 folders/groups of PDFs, each one of which has PDFs for each chapter, appendix, TOC, etc. from a textbook that I scanned into my Mac. But there appears to be no rhyme nor reason as to which document thumbnail appears. Oftentimes, it’s the TOC PDF (I always placed the cover of the textbook at the start of my TOCs) but not always.

Here’s the first group (Barron’s…workbook), for which the “Table of Contents” file is used on the icon:

Here’s the second group (Barron’s…Calculus), which uses the file “9 - Differ…equations” for the icon:

I’ve discovered a workaround to always get the icon as I want it… but it makes no sense to me: I have to open a group, change the sorting within the group from “by Name” to “unsorted,” and then drag the file I want as the icon to the first position.

…Voila?! (The new icon stays in place even after changing the in-group sorting back to “by Name.”)

What the DEVil is going on?

[BLUEFROG]

Welcome @DashingDave
I have confirmed the behavior where the first unsorted document serves as the overlay item, even after changing the sort method again. Development would have to comment on this.

[cgrunenberg]

@BLUEFROG

I have confirmed the behavior where the first unsorted document serves as the overlay item, even after changing the sort method again.

The UI settings do not matter, the first thumbnailed document is used (unsorted, natural order). But the ratings matter, meaning that the thumbnailed document with the highest rating is preferred.

[DashingDave]

What is the “natural order?” Does that mean the document that is imported first when adding a folder of documents to the database? If so, given that the order in which a folder’s documents are imported seems random, should I just always import the document I want to be the “icon” first before then importing everything else?

[cgrunenberg]

@DashingDave

Does that mean the document that is imported first when adding a folder of documents to the database?

Right.

should I just always import the document I want to be the “icon” first before then importing everything else?

You could assign the highest rating to your preferred document.

[DashingDave]

Okay—thanks for clarifying all that!