My apartment building, like most, is weird. These 2 items were sitting on top of our mailboxes. Do they contain:
  1. Water
    Most likely answer, but the fact there are 2, look similar yet both have had the labels removed and placed so precisely, invites speculation.
  2. Vodka (or other clear alcohol)
    Not so crazy, as it's a good way to booze in public and to not booze alone.
  3. Pee
    At least they're hydrated.
  4. Contact solution
    If you're out and need to borrow some.
  5. Gatorade
    Not one I thought of at first, but could be a sugar-loaded "Cool Berry Blast" and also fits with the sports-like bottle.
  6. Paint remover (acetone)
    I used to build models as a kid. I was terrible at it but I did have clear solution like this to wash my brushes after sloppily assembling an airplane / tank / car.
  7. Other.