#YASummerShowdown

It’s a metal folding chair.

From AVLFYA:

Since this is a simple question of identity, we'd only have to ask a simple question to see if Draco-Harry tells a lie as an answer or Harry-Harry tells the truth. If we really wanted to get under Draco-Harry's skin and be offensive, we'd ask “Are you a mudblood?” Draco-Harry would be forced to answer “Yes” while Harry-Harry could answer “No” (and fuss at us for using such an offensive term). So, it really doesn't matter which one we ask the question to, we'd be able to figure out who was who by the Yes or No answer. 

From FAYFYA:

1) You can ask either of the Harrys, “Have you been in the Room of Requirement?” Because both Draco and Harry have been in the Room of Requirement, the true Harry would answer yes and Malfoy, whether he is lying as himself or as Harry, would answer no. 

OR

2) The question, asked to either, is "If I asked which one of you is the real Harry Potter, which one would the other Harry Potter point to?"

From KCFYA:

It doesn't matter who you ask, you'll still get the right answer. We'll call them Lying Harry and Honest Harry, since we don't know which one is the real one. You ask one of the Harrys, “Answer yes or no, would the other Harry tell me that you are the real Harry?” If the Harry you ask is Lying Harry, he will lie and say “Yes, that Harry will tell you I am the Honest Harry.” That means you you can be sure the Harry you are speaking to is the Lying Harry. If it turns out you've asked the question of Honest Harry, he will truthfully tell you “No, the other Harry will tell you I am NOT the Honest Harry.” This once again points you to Honest Harry. You always choose the opposite person you have been told. They've ratted each other out.

From FYAON (Presuming that we are in a meta world where we are both readers who know what the series' omniscient narrator knows and Hogwarts students who know Harry): 

Daily Schedule:

Landscape with Invisible Hand (Art) The Map from Here to There (Human Geography) The Calculus of Change (Calculus) The Poet X (English) The Radius of Us (Geometry) Love & Other Carnivorous Plants (Biology)

Extracurriculars:

Pet: Popsicle, ghost, yellow lightning bolt

Aristotle and Dante Discover the Secrets of the Universe: Horse, Virgo symbol 

Aurora Rising: Neck tattoo, purple lightning bolt

Swing: Blue star on notebook, arrow

Rayne and Delilah: Birds, stars

Like a Love Story: Wings, red hearts

Darkest Part of the Forest: Octopus graffiti, white flower, green frog

Wayward Son: Sunglasses, Pride heart rainbow bumper sticker, butterfly

Me and Earl and the Dying Girl: Sunflower, dandelion

Babysitter's coven: Deathly Hallows symbol, moon and stars

Famous in a Small Town: Flamingo, shooting star