Usually used to refer to a flatterer, the Russian word подлиза literally means a downlicker: the prefix под- means down, below, beneath, or under, and the root -лиз- is common to Russian words about licking (лизать, лизун, etc.), so the whole word can be literally understood as someone who licks from below.
I am curious as to exactly what process is a flattering compared to when the flatterer is referred to as подлиза. What is the flatterer figuratively implied to lick, or what was the underlying logic when this word came to existence?
I tried to find the answer on my own and did research on the Internet, but found only explanations of the morphological composition of подлиза, so I hope that native speakers can shed some light.