In all the games of Pokemon I've played, I almost NEVER evolve my Eevee... Mostly because it's just plain cuter that way... The pic makes a good argument for Espeon, but they just don't look that nice evolved in the games...
While Eevee is still looking vulpine there, Espeon has a definite air of KITTY! about it.
Which is odd, given that, stereotypically speaking, you'd expect Espeon to be more doglike and Umbreon to be the catlike one, given the day/night associations.