Not really

You are comparing 2 non-smartphones (2 SE models) to a smartphone with a large hi-res display.

I've scanned barcodes off my screen several times (and can even use the camera in my phone to SCAN the barcodes themselves).

If you had owned anything with a decent screen resolution then yes, you would have been able to do what the iPhone can do ages ago.

Now I will say this; what you did is probably EASIER on the iPhone, that is one thing that is revolutionary. The rest is just what any modern smartphone can do.

That said; couldn't you have just swiped your CC at Sears? You don't HAVE to scan the barcode Last time I did a merchandise pickup I also didn't have the pickup slip with me, so I just swiped my card and the merchandise arrived within 2 minutes. And I didn't even need an iPhone.