Test that value contained in MutableState is updated correctly

Question

I have a viewModel that looks like this

class PhotoViewModel(
    private val getPhotoUseCase: GetPhotoUseCase
) : ViewModel() {

    val photo: MutableState<PhotoItem?> =
        mutableStateOf(null)

    fun getPhotoDetail(photoId: Int) {
        viewModelScope.launch {
            val photo = getPhotoUseCase(photoId)
            photoDetail.value = photo
        }
    }
}

and I am trying that the state is updated by doing as following

@Test
    fun `state is updated correctly`() = runTest {
        coEvery {
            getPhotoDetail(id = 0)
        } returns PhotoItem(
            ...
        )

        systemUnderTest.getPhotoDetail(id = 0)
        val actualState = systemUnderTest.photoDetail.value

        assertEquals(mockedPhotoItemUiModel, actualState)
    }

But unfortunately the test fails because the objects in memory are compared, so I get

Expected :com.package.PhotoItem@3791f50e
Actual   :com.package.PhotoItem@574b7f4a

Should I use another method for asserting the equality? Am I using a completely wrong approach by testing mutableState like this?

I couldn't find any official resources about testing MutableState except for this SO post