In the customization step, where you can drag the photo to the desired position on the product, you can also see your collection with all photos.
On mobile, this looks like shown below:
Unfortunately, if you added more than two images, you can't get to your third (or even fourth) image in the collection. This is where the arrow points at.
Because a drag and drop operation is interpreted as "dragging the photo onto the product", you can't scroll with the drag gesture on devices with touch screens.
In the example above, you'd want to scroll to the right, which is not possible. That area should probably expand so that scrolling is not necessary.
In the customization step, where you can drag the photo to the desired position on the product, you can also see your collection with all photos.
On mobile, this looks like shown below:
Unfortunately, if you added more than two images, you can't get to your third (or even fourth) image in the collection. This is where the arrow points at.
Because a drag and drop operation is interpreted as "dragging the photo onto the product", you can't scroll with the drag gesture on devices with touch screens.
In the example above, you'd want to scroll to the right, which is not possible. That area should probably expand so that scrolling is not necessary.