One pictures says more than a thousand words, and this is particularly true when studying languages. Relating a word to another word is not a very effective way of remembering it. But if you relate it to a picture then remembering it will be a lot easier.
In my mind, adding a picture to the flashcards does not seem all that complicated. Maybe just change keyword to pictures instead (In all my years skrittering, Ive never used a keyword).
The picture would not have to be very big, just 1.5x1.5 inches or even less (mobile version). And with pictures that size, they would not take up that much space either.
Just an idea that would enhance the skritter experience A LOT!