"We are seeking girls for the theater."
Translation:Hledáme děvčata pro divadlo.
In English it is possible to say either: We are seeking girls for theater, meaning the same as, We are seeking girls for the theater, and this is because even with the definite article, we could be talking about the theater in general and not a particular theater.
So I can understand leaving out the "to"/then theater in this case as it says the same thing, hiring for theater work in general. ValdaFu says it could be used to mean "that theater" so I think "this theater" is fine also. I must think about "to divadlo" for 'the theater' some more, though.
Acceptance of attributively used THIS (say, this car) for similarly used TEN/TA/TO (to auto) is not something we are prepared to do at this moment. Czech TENTO/TENHLE forms can be used almost everywhere the attributive THIS works in English, so this allows us to go for the slightly simplified mappings THIS-TENTO/TENHLE, THAT-TEN/TAMTEN/TAMHLETEN, and THE-TEN/0.
That last bit is really related the one of the main pain points in this course and learning between these two languages in general: Czech often using its infuriating word order where English makes the distinction using its infuriating articles. This means that beginning to intermediate learners have built-in resistance to accepting the other language's way of things.