I added this as a comment to a suggestion that shows as being completed yet isn't formally marked that way (it was from March 2020, so yeah, I figure maybe that i doesn't get dotted!), and since i'm not sure comments to addressed suggestions are monitored, I'm reposting here.

I think subject of suggestion says it all. Basically, the idea is that you might shoot something off-center that you want as a feature photo for a session (that's how a large wrap I made of my own wedding is composed: we're off to left side of frame in rule of thirds composition. Assuming the feature photo shows on center, then my wife and I wouldn't be in the image selected to be shown as the photographer's best picture from the Session if viewed on a phone, which cuts a vertical sliver out of a horizontal image - you'd just see like some foliage. By picking a focal point, this can be avoided.

https://help.pixieset.com/hc/en-us/articles/115003793312-Updating-a-Collection-s-Cover-Photo#h_01J5VHB6X0B794Z0DNCFS29G96

The original S+ feature suggestion is here: https://studioplus.uservoice.com/forums/560392-studioplus-product-suggestions/suggestions/17338465-what-image-to-be-seen-when-logging-into-inspired