HiDPI image: why scaled?

I dropped an image from disk into the navigation pane.
I dropped a second version (twice the width/height) into the @2 area and get:

What does it means ?
Why will it be scaled ?

Nota: at first, I dropped a version with the same width/height, but at 144 dpi (instead of 72). I got a message too, so I changed the image specs.

BTW: these images are resized down from a greater and 300 dpi image.

423 is not 424, the double of 212, so it must be scaled.

Text in red comes from Xojo.

My resize respect L/R values…

I understand, but I hope Xojo adds a pixel, not resize it to 424 (with same width…)

Thanks Carsten, I do not noticed this subtle difference (with my old and tired eyes).

That’s how Xojo adds missing pixels, resizing the image to cover the missing part.