Sentence 1 under suggests that EX-port restrictions help national production. But how?
I understand how IM-port restrictions help "domestic market" (from sentence 2) and "national production" - IM-port restrictions dragoon your nationals to buy from national producers that you're protecting under your protectionism.
What's "the expense of the trade of other Member States"?
Sorry for long quote. Let me know how I can pare it.
Craig, P and De Burca, G. EU Law 6 ed. 2015. pp. 677-678. All emboldenings are mine.
(C) INDISTINCTLY APPLICABLE RULES: ARTICLE 35
Article 35 prohibits quantitative restrictions and MEQRs in relation to exports in the same manner as does Article 34 in relation to imports. The ECJ has, however, held that there is a difference between the two provisions. Whereas Article 34 will apply to discriminatory provisions and also to indistinctly applicable measures, Article 35 will, it seems, apply only if there is discrimination. An exporter faced with a national rule on, for example, quality standards for a product to be marketed in that state cannot use Article 35 to argue that such a rule renders it more difficult for that exporter to penetrate other markets. The rationale for making Article 34 applicable to measures which do not discriminate is that they impose a dual burden on the importer, who will have to satisfy the rules in its own state and also the state of import. This will not normally be so in relation to Article 35.
This was established in Groenveld. Dutch legislation prohibited all manufacturers of meat products from having in stock or processing horsemeat. The purpose was to safeguard the export of meat products to countries that prohibited the marketing of horseflesh. It was impossible to detect the presence of horsemeat within other meat products, and therefore the ban was designed to prevent its use by preventing meat processors from having horsemeat in stock at all. The sale of horsemeat was not actually forbidden in the Netherlands. Nonetheless the Court held that the Dutch rule did not infringe what is now Article 35.  The Article was aimed at national measures which had as their specific object or effect the restriction of exports, so as to provide a particular advantage for national production at the expense of the trade of other Member States. This was not the case here, said the Court, since the prohibition applied to the production of goods of a certain kind without drawing a distinction depending on whether such goods were intended for the national market or for export.
It has however been argued that Article 35 should be conceptualized in terms of market access, and that it should be capable of applying to indistinctly applicable rules. It is moreover clear from Gysbrechts that the ECJ is willing to find a breach of Article 35 even where the rule applies to all traders if it has a greater effect on exports than on domestic traders. Belgian law prohibited a supplier in a distant selling contract from requiring that the consumer provide his payment card number, even though the supplier undertook not to use it to collect payment before expiry of the period in which the consumer could return the goods.  The ECJ cited Groenveld for the proposition that Article 35 caught national measures which treated differently the domestic and export trade of a Member State so as to provide an advantage for the domestic market at the expense of trade of other Member States. It noted that the consequences of the prohibition in this case were generally more significant in crossborder sales made directly to consumers, because of the obstacles to bringing legal proceedings in another Member State against consumers who defaulted. The ECJ therefore concluded that even if the prohibition was applicable to all traders active in the national territory, its actual effect was nonetheless greater on goods leaving the market of the exporting Member State than on the marketing of goods in the domestic market of that Member State and was therefore caught by Article 35. It held moreover that although consumer protection could constitute a justification, the challenged rule was disproportionate.