Explore the symbolic significance of the following symbols in Section II, using textual evidence and commentary for each. the "thrush"/bird the picture of the church and the rhyme the telescreen the clock the glass paperweight

The thrush bird that sings foreshadows the older prole woman continually singing the same song as she hangs out laundry. They both have beautiful voices and represent the elemental beauty of nature. It is significant that Winston and Julia hear both of them in places of refuge, away (they believe) from the world of the Party, where they too can behave as elemental creatures of nature. Quotes about the thrush can be found at the end of part II, chapter two, and quotes about the old woman can be found scattered throughout part II—for example, in chapter four.
The picture is of the church of St. Clements. As Mr. Charrington says,

It was a church at one time, St Clement Danes, its name was.

Mr. Charrington goes on to recite the rhyme associated with the church:

Oranges and lemons, say the bells of St Clement’s . . . Here comes a chopper to chop off your head.

Both represent to Winston his longing for an earlier time. The rhyme also symbolizes Winston's ignorance: only too late does he associate the rhyme's grisly ending with his own fate.
Julia and Winston think they are free of the telescreen in the room above Mr. Charrington's shop, but it is behind the picture of St Clement's, watching them all the time. Again, St. Clement's is a deception used to lure Winston to his doom.
Right before and right after he is arrested, Winston notes that the clock on the mantelpiece in the room above Mr. Charrington's shop is wrong. This symbolizes that, from his arrest onward, he will no longer have a normal notion of time. The Party has taken over his reality:

He noticed that the clock on the mantelpiece said nine, meaning twentyone. But the light seemed too strong.

The glass paperweight is an important symbol. Winston associates the beautiful bit of coral within the paperweight's wavy glass with the room above Mr. Charrington's shop and with his relationship with Julia. He feels that he and Julia, too, are encased in a metaphoric protective glass. As they are arrested, this illusion is shattered, just as the paperweight itself is shattered by the Thought Police. Quotes about the paperweight shattering can be found at the end of the last chapter of part II, when Julia and Winston are arrested.