Well, not exactly... You are to send two new photographs instead of the ones they did not approve. But beware - you have just about 3 attempts to pass their test. Or at least it was so when I did the entrance test...
So may good fortune be yours :-) I hope you will pass for the second time...

hard to tell from the image you posted -- is it still sharp at 100%??? looks like some of the white hightlights might be blown -- for me, it 's a great image - well composed & good contrast between the gree n& the b/w -- for first submissions MS sites get really techinical though.

 re image uniquemess, it's not so much whther there are other images of this species but rather of all butterflies in general, since most buyers probably dont care about the particular species.   it doesnt make a lot of sense, so it's just one of the hurdles you need to get past -- you might want try a less well covered area if you can on your first submission.

steve

For acceptance at iS, shrink the size of your submision to 2400 X 1800. Compressing the pixels should kill the Overfilter thing and help get rid of the noise.  Do not over sharpen; if you use the Unsharp mask, use only a light setting for iS (Amount 50, Radius 12 and Threshold 1).  Using Sharpen or Unsharp with higher settings will usually result in Overfiltered rejections.  For iS, I don't punch up color at all!  Sites vary.

Regarding the number of tries at iS:
If you get one accepted the first time, you get to submit two more images within a week (I waited 5 days for the second try); if they accept one of the two, you will have to wait two weeks (10 days).  On the third try you are submitting one image and if it gets rejected, you will have to wait 30 days to try again.  Whether they cut you loose after the fourth attempt, I cannot say.  It took me four tries.  Every time the images were rejected for either "Overfiltering" or "A few Stray Pixels" (Isolations).    I relied on my best selling images, but iS is the pickiest site there is on Isolations!!!  After being accepted,  I tried several isolations that are doing well on other sites; they were shot down by iS for "A few stray Pixels" which I could not find even at 200%.  Do not use isolations over  white or black for gaining access!  The last image accepted of mine for entry was a straight photograph of a colorful private plane taxiing with no post procesing except slight touch with levels.  That shot was accepted on every site I am on, but no sales on it yet after 4 months.  Go figure.  Glad I made that choice for my fourth attempt.  I was thinking I would have to wait two months (60 days) to try again or I would get the axe. 

I made it though!    Now I think I will be able to meet their demands.  Funny thing is - when I uploaded the three images that were approved for entrance for my portfolio, The three were rejected for Overfiltered.  I backed off the color a bit (which works for most sites) but they were shot down for "Artifacts".  So I sent four new images, and they got accepted.  I have been with them for a month and have one sale.  Obviously I have to get my inventory up.

..THANK YOU ALL! My initial set was approved on Saturday! after my resend  with 2 new pics  they approved them! Now I`m  in portfolio-loading status! Than you again! Cheers