The socialist fraternal kiss was a special form of greeting between socialist state leaders. The act demonstrated the special connection that exists between Communist countries, consisting of an embrace, along with a series of three kisses on alternate cheeks. In rare cases, when the two leaders considered themselves exceptionally close, the kisses were given on the mouth rather than on the cheeks.
Here is a photo of a Soviet and an American soldier sharing a 'socialist fraternal kiss', Germany, 1945:
I find the most hilarious part to be tankies also defending Putin. It's almost like they're more pro-authoritarian than they are pro-worker... or just a psychological warfare operative doing a misinformation campaign?
The text at the bottom reads "My God help me survive this deadly love".
Which fits the relationship between the Soviet Union and the German Democratic Republic perfectly.
That mural on the Berlin wall is very popular in tourist shops there.
The NATO themed gift shop near Checkpoint Charlie has a really large collection of items with the image plastered on. Was surprising, to say the least.