I assume the building with the new mural is this one https://www.openstreetmap.org/way/127497678 Looks like it matches the article.

The correct tags for the mural are `tourism=artwork` + `artwork_type=mural`. Normally, these are attached to the building wall on which they appear.

For the building, which looks like a boiler house (katlu māja), it would be `power=generator` with `generator:output:heat=yes`. There are other tags like `generator:type`, `generator:method` and `generator:source`, but I have no idea what these are for this one.

I'm afraid I don't use or know enough about Organic Maps to say how to do this there and how to specify the tags. It might have a mural preset. I doubt there's a boiler house preset.

I fixed this here for now as far as I understand it.