@Fischl: This is the explanation of the Menorahs, taken from here:
www.bromptonoratory.co.uk/provost-blog (scroll down)

FEBRUARY 2019 LETTER FROM THE PROVOST

January 31, 2019

Visitors to the Oratory Church are often surprised by the Jewish-looking candelabras on either side of the sanctuary. The Oratory ‘menorahs’ are probably as close as anything in existence to exact replicas of the original lampstand that was placed in the antechamber to the sanctuary of Herod’s Temple in Jerusalem. They were a gift of the 3rd Marquess of Bute, who was received into the Catholic Church in 1868 and commissioned William Burges to copy them from a marble relief on the Arch of Titus in Rome, where booty from the Temple was carried in triumph after the destruction of Jerusalem in 70A.D. The Temple Menorah is believed to have been destroyed some time after the Vandal invasion of the fifth Century.

The Oratory lampstands were placed in the sanctuary in testimony to our belief in the continuity of the religion of our Jewish forbears with our own religion as Catholics today. They testify to our conviction that the Old Testament has found its complete and definitive fulfilment in the Church which is the New Jerusalem. The Presence of God that once dwelt in the Temple’s inner sanctum is now enthroned in the hearts of all who have been made members of the Mystical Body of Christ through Baptism. The new Holy of Holies is to be found in the Altar, on which Our Lord makes Himself present at every Mass, and where He remains day and night in the Tabernacle. A Catholic church, then, is a holy place, and when our friends tell us that they do not need a church to pray in – that they can do it just as well on a hillside or in the bath – then we can say to them: Yes, it is always a good thing to pray wherever you are and whenever you can. But there is nowhere else on earth today where we find Our Lord present in the same way that He is present on the Altar and in the Tabernacle.

Given our unwavering insistence on the unique sacredness of our consecrated buildings, non-Catholics are sometimes genuinely taken aback by the atmosphere of informality that tends to pervade in our churches. Converts to the Faith have to get used to the way that ‘cradle’ Catholics seem to pile into church at the last possible moment, and potter around lighting candles and visiting the statues of their favourite saints even after Mass has begun. Perhaps such casualness should be frowned upon. But such familiarity probably has its source in a religious instinct that is quite healthy. After all, as disciples of Christ there is a sense in which we inhabit this world as exiles in a foreign land. Coming to Mass, visiting the Blessed Sacrament and communing with the angels and saints is probably the closest that we shall ever get to coming ‘home’, at least on this side of Heaven. And home is exactly how we should see a church or chapel where a flickering lamp tells us that Our Lord in is residence and waiting to receive us into His royal Presence. This is a King who has ennobled us by pouring a participation in His own life into our hearts in Baptism; a King who invites us into intimate union with Him by feeding us with His own Body.

At the same time, of course, we always have to be careful to ensure that familiarity never breeds contempt. In the Gospel, Our Lord expels the racketeering traders from the Temple because they have profaned the House of His Father. As He drives them out with a homemade whip, the disciples are reminded of a verse from Psalm 68: “Zeal for thy house hath devoured me.” On the practical level, zeal for the Father’s House means that we should certainly make every effort to act accordingly in any place that is consecrated to the worship of God, doing our best to arrive on time for Holy Mass and respecting the sacred purpose of our surroundings. Parents should teach their children to genuflect and to receive Holy Communion with real devotion, and set a good example by making a prayer of thanksgiving with them afterwards. But Our Lord’s cleansing of the Temple is not primarily a lesson about outward decorum in church. It relates very much to our interior dispositions. After all, thanks to our Baptism, each one of us is a living Temple of the Holy Ghost. As such we have to be purged of everything that does not belong. The Holy Ghost cannot be expected to co-habit with gossip, unkindness and conceit. Our Lord gives us the example of an impeccably punctilious Pharisee who is so proud of his own piety and yet defiles the Temple by looking down on a despised publican who is too ashamed to lift his head. It is the publican who returns home in favour with God.

To help us all pray at Mass on Sunday mornings, the Oratory provides a room in St Gregory’s Library, near the main entrance to the church, where parents can take (and must accompany at all times) any of their young children who become restless. But the room is certainly not compulsory for all children, some of whom are capable of enduring a whole Oratory sermon without so much as a single yawn or a squeal. We are blessed to have world class choirs singing at many of our liturgical functions. But that does not make the Mass a concert, and if a child expresses her indignation at the length of the proceedings with an occasional howl, then we should avoid Medusa-style glaring and hissing at all costs. The Oratory menorahs are a reminder that we are all of us called to be united in charity as God’s chosen people. Never let it be said that we are God’s frozen people.
Fr Julian Large