From the Media tab while editing an app in Splunkbase:
Recommended screenshot size is 1200px by 900px
When you click a screenshot thumbnail on the app page, Splunkbase presents a larger version of the image in a popup. The constraints of that popup's CSS means that, in 1200px by 900px screenshots of app dashboards, text is unreadable (unless you've used "zoom" in your browser to enlarge the text; but that introduces its own issues).
What resolution should I use to ensure app screenshots are readable in Splunkbase?
(By the time you read this, it's possible I might have updated those screenshots again, possibly further tweaking their dimensions.)
Related tip: I deliberately named the screenshot image files "...-1.png", "...-2.png", etc, where the number indicates the order in which I want Splunkbase to display them in its image carousel. I was also careful to upload the files in that order. Nope. That didn't work: Splunkbase displayed them in reverse order! I deleted all screenshots, then re-uploaded them in reverse order (-5.png, -4.png, etc.). Yep, that worked. Counterintuitive!