。
Could you show me a different one?
Literal
Different-one [object-を] show receive-could-not [question-か]?
見せてもらえませんか uses the negative potential of もらう to create a very polite request — 'couldn't I receive the favor of being shown?' The negative form is paradoxically more deferential than the positive. Compare the bluntness scale: 見せて < 見せてください < 見せてもらえますか < 見せてもらえませんか.