The solution is quite simple: pical doesn't fall back to English when it doesn't find your language. Hence it gives you the language codes and not the translation.

A quick and dirty solution is copying the "english" folder in the "language" folder and naming it after your language (in your case russian). Now the module should show up in english. You can now start translating the module to your language if you wish by editing the files in your new folder.

I'd like to ask the programmer of this wonderful module (I truly love it!) to fix this problem. I believe the problem lies in pical.php round about line 123 where the module seeks a present language module but can't find the "english" folder.