Sometimes it\'s a crap shoot!
Sometimes you get the people who vote solely on their favourite army and sometimes people who are heavily orientated towards the painting side.
Of the two pictures you id\'d as having such a disparity here\'s my 2 pence worth:-
The Blood Angel with a smaller picture is less likely to show errors/areas that need improvement.
The Dark Angel, however with a much bigger picture does show a number of areas which could do with improving.
The cloak has a granulairty which makes it look as if you\'ve drybrushed it and then tried to work the highlights up.
The Armour is really lacking in strong variation between the darkest (shadow) areas and the highlights. And the Helmet looks as if the paint is really thick and undiluted with little or no definition of shadow tones.
Having said all that, it is not a \'Bad\' figure and considering you got $75 for it, what\'s the problem?

In the end what really matters is that you were/are happy with the results and you got pleasure out of painting it.