Why some services show pics and others don't

[michael b]

Apologies if this has been asked before - does anyone know the reason why some services show a thumbnail pic in the 3 pack i.e plumbers but say locksmiths and hairdressers don't?

Thanks,

Michael

 

[michael b]

So I had more of a look.

So these services DO show thumbnail pics in the 3 pack etc:
Plumbers / kitchens / Carpets / Flooring / Pest Control / Air Con etc

So these services DON'T show thumbnail pics in the 3 pack etc:
Locksmiths / Builders / Electricians / Accountants / Dentists etc