No I wouldn't say that is a harlequin. To my understanding the harlequins are when there is a very dark purple splash which almost looks painted on one side of the flower (rather than the pigmentation being all the way through the depth of the petals, you can see the colour on the other side but it looks like you are seeing it THROUGH the usual colour on the back.
The splash like this is more like a standard pigmentation that is on the back as well.
Maybe I've always mis-understood harlequin but I think a search for that term will bring up something quite different to this. Here's a link to an example of a harlequin.
Phalaenopsis 'Elegant Harlequin'
I'm not really sure what I would call the ones with the splash like this. I know at home I have the name of a hybrid that looks like this but I can't bring it to mind. If I remember when I get home I'll try and look it up but I've been having trouble remembering to do things in the evenings recently so my apologies in advance if I don't come back to you.