i suppose they could, if the shielding player is on a platform, but not conventionally-cancelled missiles...some of the hitbox would certainly be below the shield, but it would hit the front of the shield first and splode.
in short, missiles != dress
DDR: want to pass Paranoia Survivor ~ Religions are just cults with more members. -- The resident SSB:M Captain Falcon user. -- "Let's eat fast so we can eat again!" ~ Ash