This is Tango's "I hate you!" face, otherwise known as "0h My God you have to do my nails again I'm going to die this time for realz I just know it!!"
Never mind Tango it'll all be over soon and you'll feel better once your nails are shorter. Give Tango lots of cuddles from us for being such a brave little soul.
It's actually a grinder. Sort of like a dremel. If I used the clippers, you'd be able to hear him scream all the way over there! And that's before I actually even start clipping! I have to pick him up and THEN go get the grinder rather than the reverse, otherwise he'll hide in places I can't reach. He's crafty, that one!
None of my dogs ever liked getting their nails clipped and I have to admit I've tended to specifically buy dogs with white or clear nails so I can SEE what I'm cutting. I hear ya though as mine would often cry and scream and hadn't even been touched yet! A good chunk of cooked meat at the end as a treat can really make it up though.