This bug has existed for the entire life of the Calypso media modal and blocks gallery flow on iOS devices. When uploading multiple images on iOS, many images are replaced with dupes of another image in the selection, typically the first image. The WP apps don’t support galleries, the core media modal is a barely usable mess on touch devices, and Calypso’s media modal blocks gallery flow. We need mobile gallery flow somewhere in WP*.
It’s hard to notice the dupe images in those shots given how few images show in the viewport at a time. To reproduce, tap to select multiple images when uploading with the media modal. Upload and behold the dupes. 100% reproducible for me.
While in the gallery editor, note the left right arrows on the first image. Tapping an image makes these active. The arrows stay anchored top left and can be used to reorder the currently selected image. Since only one row of images shows at a time, I’m often reordering offscreen images. Scroll down to select an image, scroll up to access the arrows, move images you can’t see. I find this awkward. Drag-and-drop is not available.
And while still in the gallery editor, try creating a visual record of screenshots and note how frustratingly useless these small, cropped images are when captioning and ordering galleries.
Here’s a better set of images that shows the flow.