Can a property manager allow a realtor to come into your place to take photos of the interior - including your furniture and personal items - to publish these online to sell the property?
RCW 59.18.150(1), which governs residential tenancies, states
The tenant shall not unreasonably withhold consent to the landlord to enter into the dwelling unit in order to inspect the premises, make necessary or agreed repairs, alterations, or improvements, supply necessary or agreed services, or exhibit the dwelling unit to prospective or actual purchasers, mortgagees, tenants, workers, or contractors.
The landlord shall not abuse the right of access or use it to harass the tenant, and shall provide notice before entry as provided in this subsection. Except in the case of emergency or if it is impracticable to do so, the landlord shall give the tenant at least two days' written notice of his or her intent to enter and shall enter only at reasonable times.
Assuming that you were given advance notice, entry is legal. There is no special provision prohibiting photographing a rental unit that contains a tenants property, so there is no statutory prohibition against this. If you can demonstrate that you were damaged by having your property photographed, you could sue the landlord. But I don't see what the damage would be. There is a common law basis for a lawsuit for public disclosure of embarrassing private facts, but it is unlikely that a realtor would publish photos that revealed an embarrassing private fact about you. There is also the tort of placing you in false public light, but again it's hard to see what fact a photograph of your furniture would fill that bill (perhaps there's a detail you're not mentioning).