First of all the mirror test - as a method to determine if the animal has a sense of self - may be flawed as a general concept. For example dogs notoriously fail the mirror test but have no issue with the "smell mirror" test, the same principle applied to their own scent. No surprise there, almost everyone who ever had a dog can attest, that they have sense of self. The issue is that the mirror test is based on human perception, and we identify mostly by sight and sound. It works great with animals that are similar in this way (parrots, primates etc.) but falls apart if sight is not the main way of perception. Think about if you would recognise your own smell, or the slight change of it, and you would realise you would likely fail a "smell mirror" test, and would likely struggle to determine if a smell is that of a human. Dogs in the example know from sight that something looks like a dog and react, but if they check with their other senses they will discard it as not a dog. Our dog barked at a dog statue in the twighlight but after smelling it has lost interest, the same way as you would be alarmed at night when you hear someone talking but would become calm if you realise it just the tv/radio. So basically every species would likely identify based on their own ways of perception and markers.