<ListView>
            <ListView.ItemContainerStyle>
                <Style  TargetType="{x:Type ListViewItem}">
                    <Setter Property="VerticalAlignment" Value="Top" />                          - не работает
                </Style>
            </ListView.ItemContainerStyle>
            <ListView.View>
                <GridView>
                    <GridView.Columns>
                        <GridViewColumn Width="24">
                            <GridViewColumn.CellTemplate>
                                <DataTemplate>
                                    <Grid>
                                        <Image VerticalAlignment="Top" Source="{Binding Icon}" />         - тоже не работает
                                    </Grid>
                                </DataTemplate>
                            </GridViewColumn.CellTemplate>
                        </GridViewColumn>
                        <GridViewColumn DisplayMemberBinding="{Binding Text}" />
                    </GridView.Columns>
                </GridView>
            </ListView.View>
        </ListView>

            <ListBox.ItemTemplate>
                <DataTemplate DataType="{x:Type local:MessageItem}">
                    <Grid>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="24"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <Image VerticalAlignment="Top" Width="12" Height="12" Grid.Column="0" Source="{Binding Icon}" />
                        <TextBlock Grid.Column="1" Text="{Binding Text}" />
                    </Grid>
                </DataTemplate>
            </ListBox.ItemTemplate>