Due to the image’s aspect ratio, our automatic 3D format detection algorithm is probably incorrectly assessing that your images are Half-Width SBS when they’re really Full-Width SBS.
There’s a few things you can do, all of which should work:
Go into LeiaPlayer’s Settings and disable “Auto-Detect SBS Media”
Add/change the filename tag for your file to be _2x1.jpg
Tap the ellipsis/kabob/three dots menu in the top right of the image, tap “Edit/Remove 3D Tag”, and select 3D > SBS > Full-Width