Premise: they are two people wearing sunglasses and a helmets standing behind a big gun.

Hypothesis: A duo stands behind a gun.
Relation: entailment

Hypothesis: They are two people wearing sunglasses at the beach behind an inflatable raft.
Relation: contradiction

Hypothesis: Two people wearing sunglasses, an old man and a young boy, with helmets stand behind a big gun.
Relation: neutral