What's 'questionable' about this?

I think 'Questionable' is the default image rating, so if you don't choose something else when you're uploading, that's what gets assigned.

So the original pun is that Haruhi says suki na ko iru? which means "Is there a girl you like?"
But she says the su part very quietly, so Kyon hears kinako iru? which means "Do you want some soy-flour (dango)?"
And Kyon in his head wonders if she thought he preferred mitarashi (dango) instead (dango with a sweet, soy sauce based syrup).

Ah, I thought my "untranslatable Japanese pun" sense was tingling.

Well Kyon better keep that pun to himself or else

Why did the other one get approved and not this?

I hope it does, translating that pun was hard.