To be honest Sam I think Mr Mann has a point.
That looks like a photo of the screen to me.....there are reflections in it.
Talking of which, I doubt this is a genuine 'marquee' as it doesn't have any 'black' in it, (looking at the part with reflections).
True 'marching ants' are scrolling diagonal black and white stripes....visible only in a 1px width outline.
What doesn't make sense though is that the 'Magic Wand' tool, (or whatever it is), is set to subtract....which can only be done [in PS] if there is something to subtract from, otherwise its disabled.....so where is that marquee?
Having a real screenshot would help....and verification this really is in PS.
'Curiouser and curiouser!' cried Alice....whoever
she is.
Regards.
MrToM.