I can see several reasons why this was passed to you.
The first is easy: there was a better card in the pack. The pack is missing an uncommon, so my best guess is a Trusty Machete. This might be considered a better choice if you're afraid of the Sphinx's high casting cost and color commitment (I'd have picked the sphinx in that situation, but go figure).
[[Trusty Machete]]
The second reason is that this pack has two very good blue cards -- the Sphinx and the Tsunami.
[[Sphinx of Jwar Isle]] [[Living Tsunami]]
That player knew that if he picked one of them, you'll pick the other and you'll end up competing with each other for blue. A sensible decision in this situation is to let you and someone else quarrel over blue, while picking a decent card from a different color and somewhat improving your card flow in the following picks.
The third possible reason is that the player to your right wasn't a very good drafter and drafted based on his personal preferences rather than the cards' true value.