Well, considering the evidence you've put forth, it's fair to say that It doesn't really have immediate significance for the Revolution, although the Russo-Japanese war was a definite precursor. It likely has to do with the destruction to Russia's reputation wrought by the war, which was the first ever war between major European and Asian powers in which the European power lost (at least in the age of Imperialism). This tarnished Russia's prestige, as it was already seen as an ageing power, a backwards and primitive empire that was struggling to keep up with the West, even if it was the largest nation on Earth. Depending on who created the cartoon (obviously not a fan of Russia or their policies), it was either a dig at the Russians or a comment on Japan as a rising power (a theme that would continue after WWI...), or even both. The cartoonist also likely foresaw a shift in the Asian balance of power with Russia now so clearly knocked out of competition when they previously held quite a bit of sway in parts of the Far East. While the author didn't necessarily foresee the Russian Revolution, they definitely did foresee the fall of Russia's strength in Asia as a turning point.

I'd also love to see the cartoon, if possible.