Picons are channel logos which are linked to one or more TV channels using a service reference or a simplified version of the channel name. They can be installed on the popular Enigma2 satellite receivers and can be downloaded from the Plugins. They can be present in the in the left or right side of the screen, in the channel list and in Webif. There are a lot to choose from, they differ in style and size, example: "snp-full.220x132-190x102.light.on.transparent" like in the picture below, the picon of the BBC is in the left corner below.
You can change a few settings concerning the picons, like where the picons will appear. Go to Main menu -> Setup -> Gui Settings -> User Interface and enable show picons in the channel selection list.
Notice: when you install the picons in the memory of our the box, they will use quite a bit of memory size. As an alternative you can install them on external media. Also a restore of an AutoBackup can take a bit more time, as the picons collection can be large, because the picons maintainers don't know which channels and satellites you will use, so there are many.