when and where do custom icons show in the location extension?
Re: when and where do custom icons show in the location extension?
Location extensions are shown when the search made has the location name or when the searcher is located close to the physical address that you targeted and the your ad must get a spot above the organic result. Only under these conditions the location extension icon could be will be displayed.
However, I have noticed that the location address is shown more often without the icon. I'm not sure how it works.
In case, you have not gone throw the below resource regarding location extension, take a look at it.