Maris ayin and kosher certification

Question

What reasoning is used by mainstream kosher certification agencies to certify food items containing only kosher ingredients but packaged and/or designed to look and/or taste non-kosher. For example, imitation crab (dyed and shaped to look like crab meat and used in sushi) or artificially flavored snacks illustrated with pictures of meat and dairy, such as this. (I'm waiting to hear back from the O-U.)

Since first posting this, I came across Halachipedia's post on this topic:

There is no maris ayin issue involved in eating surimi since people know that surimi shrimp etc exists, we do not have to worry that one will think he is eating a non-kosher product.

They cite as a source for this argument Halachically Speaking (vol. 5, Issue 12, p. 3) which actually does not appear to present any reasoning at all(?), (though there may be more information in the Journal of Halacha and Contemporary Society 50 p.107, cited in footnote 10) which I have yet to obtain.

As a counterpoint to this argument, the New York Times recently seemd to feel the need to clarify the artificial source of the crab in kosher-certified California rolls:

Orthodox Jews are eating dragon rolls, rainbow rolls, tsunami rolls and California rolls (using imitation crab)...

Answer 1

As Rabbi Yehuda Spitz explains, for many dairy-look pareve products there is an understanding among the general population that, even though it looks like it's dairy, it's not, and, because of that understanding, there's no need to specially indicate to people that the product is pareve. Even for those who wish to be more stringent, he explains, and even for products without such an understanding, it's sufficient to have a product label indicating the pareve status. He's referring to meat and milk issues, i.e. whether a dairy-look pareve food can be served with meat. Likely, then, the same would apply to the question of whether a meat-and-milk-look product can be served at all, and perhaps also to the question of whether a non-kosher-species-look product can be served at all. Then a label indicating the kosher status would suffice — and these products have that.

Answer 2

Halachically Speaking (vol. 5, Issue 12, p. 3) does give a reason for permitting kosher food which imitates non-kosher food. It quotes the Gemorah in Chulin that says that “Yalta the wife of Rav Nachmun said that for every non-Kosher food there exists a counterpart which is Kosher. In response to this, her husband ordered that one of the foods be heated for her.”

It goes on to say that the reason why Hashem did this is to give Klal Yisroel reward for watching the mitzvahs, quoting a Medrash Tanchuma.

The fact that Rav Nachmun acted as he did and is not criticised by the Gemoro shows it is permissible. The Medrash Tanchuma gives a reason why the ersatz foods were provided by G-d.