A suggestio would be to make espeon's ears a little bigger and color her/him a bit more purple-ish, because i thought he/she was a mew at first! :0
Still love it though! My favorite is vaporeon >3<
Also, espeon has no sideburns.
I love it. Its cute how glaceon is patting eevee's head, and in real life that would be so cute! >w< You balanced the picture very well colourwise (you know because they are all different colours and stuff)
In the chibi form they all have smaller ears and tails than normal, and brighter colors =^_^= But I sure did forget those side burns O_o *ashamed* Haha, now that you mention it, chibi espeon do almost look like Mew