Snapshot size differs between Xcode and Fastlane

[ChrisLawther-KitmanLabs]

We have some very straightforward snapshot tests in an SPM package that have produced reference images at 3x, and which reliably pass when tests are run from within Xcode.

If the same tests are instead run from Fastlane (on the same machine), they fail. The failed images are at 2x dimensions.

An example of our usage is a very straightforward:

assertSnapshot(matching: someVc, as: .image(on: .iPhone13(.portrait), perceptualPrecision: 0.98), record: false)

Why might the size vary if we're always asking for .iPhone13(.portrait) ?