I wonder why Etsy is displaying listings in 3x2 ratio when you make an ordinary search in the orange Etsy app, but if you search for a shop, then the listings in the shop is displayed in 1x1 ratio. And cropping left and right side of the image.
I hope someone from Etsy reads this and correct it so that the listings is displayed in the same ratio everywhere.
Not having the same ratio on images makes it hard to create good looking images!
Thumbnails are 5:4 (edited after I checked) in search and in your shop (on the website). I'm not sure if it's different on the app.
Within the listing the aspect ratio of the images is determined by the ratio first image you upload. It can be any ratio. Subsequent images in that listing need to be the same aspect ratio as the first one otherwise you see white space top and bottom or left and right.
I like my listing photos square, but I need to keep in mind that the top and bottom will be cropped off when the thumbnail is generated.
I just re-read your OP. I don't use the app but if what you are saying is correct about the 3:2 thumbnails then I have no idea how my images look as thumbnails. I wonder if that's why I don't get many sales now because too much would be cut off. I agree it should at least be consistent across the website and app.