As a general rule, I think it would be best to, as I said, resize for the purpose. With NGE, it's fine to post full-size caps if further shrinking would obscure important details, but, if nothing is lost by shrinking it 3/4, 1/2, 1/4, whatever, do that instead.
When it comes to NME and its Blu-Ray resolution, I can't think of any reason why we would need to post original resolution on the wiki (except in really rare cases). Same principles apply -- shrink it to the purpose.
I was suspecting that it comes from the Collector's Discs; if that's the case then I suppose that the picture should be reverted back.
Done.