In this case, Akela is appealing to Mowgli's sense of compassion. When one gives a look of pity, he knows that Mowgli has a tough decision to make, especially since Akela has always abided by the laws of the jungle. But in order for Akela to live, he must appeal to Mowgli's sense of compassion for life of all creatures thereby putting the law of the jungle by the waist side. The evidence is not really presented here, so you will need to look for pieces of evidence that show Mowgli being a compassionate character.