Biomarkt = store with organic foods; often a health food store
In the past, I've written about "parking" dogs outside of stores. It's not uncommon for Germans to bring their dogs with them all over the place, and it's also common that many places allow dogs. However, supermarkets often don't, probably for hygienic reasons.
When we were visiting Heidelberg, we walked by a biomarkt and saw these patient guys waiting for their owners to return.