What is this canister at the top of a utility pole?
It's a distribution transformer, aka 'pole pig'. It lowers the voltage from the higher voltage in the supply lines to the power used in your house. The distribution lines that run down your street are probably 5-15kV. From the length of the insulators, probably towards the higher end of that spectrum. They contain a transformer and oil used for cooling (in earlier days that oil would contain hazardous PCBs - PolyChlorinated Biphenyls, not printed circuit boards, though I do have a warning sticker on my computer that says it contains PCBs). 

Since Costa Rica uses 120VAC/60Hz the secondary voltage probably is center-tapped 240VAC 60Hz as used in Canada and the US. 

At a higher level in the distribution food chain, the electricity is all 3-phase but it's common to only distribute the 3-phase along major thoroughfares and then bring a single phase down a smaller street. 

These are quite common in North America - in rural and in suburban environments. Only in major cities where the utilities are kept underground are they not seen. 

Edit: The IC is probably part of the ICE logo (Instituto Costarricense de Electricidad), the state-run electricity (and telecom) company.