The DUP has called on the new Secretary of State to reinstate a portrait of the Queen at Stormont House.
Party leader Arlene Foster said it was ridiculous that it had been removed.
"It is beyond parody that there is a dispute over a portrait of Her Majesty the Queen, our head of state," she tweeted.
"Stormont House is the seat of HMG (Her Majesty's Government) in Northern Ireland. All of this is the opposite of HM's gracious and generous approach."
It emerged last month that the portrait had been removed from the Northern Ireland Office (NIO) base in Belfast after compensation was paid to a civil servant over it.
Lord Maginnis told the House of Lords that a civil servant had been paid £10,000 in compensation for being offended at having to walk past portraits of the head of state and her husband, the Duke of Edinburgh.
The Belfast Telegraph yesterday asked the Northern Ireland Office (NIO) five questions about the dispute over royal pictures on its premises.
The NIO has not yet responded to the questions.
Secretary of State Julian Smith has revealed there is a photograph of the Queen in his office in Stormont House.
He tweeted an image of it and said: "Proud to have a picture of Her Majesty The Queen on the mantle (sic) piece of my private office at Stormont. I was delighted to see it there when I arrived last Friday."
Mr Smith's tweet contradicted reports that pictures of the Queen have been removed from Stormont House.
However, DUP MP Gavin Robinson said: "Whilst the Secretary of State has a small photograph of Her Majesty the Queen in his office, this does not address the wider issue. He needs to act.
"The Equality Commission has explained how these photographs were not automatically incompatible with the work environment.
"The Secretary of State should engage with the Equality Commission to understand the parameters."
Mr Robinson called on Sinn Fein to "give leadership on this issue" and show that they "respect the constitutional reality".
He said: "When people say they want respect and tolerance, it is important that these very attributes are shown to the position of Northern Ireland where the head of state is the Queen.
"There should be an acknowledgement that people have an identity, which should be displayed in an appropriate way.
"We cannot have a society in which we strip colour and identity out. That will only ruin community relations and will not help society to move forward together."
The East Belfast MP said his party had raised the issue with Prime Minister Boris Johnson and Mr Smith.
"There should be a sensible approach to issues like this. The portrait should be reinstated forthwith," he said. "The Northern Ireland Office should reflect the reality that it is a branch of the United Kingdom Government. There is no shame in that."
In a statement, Mr Smith said he wouldn't be commenting on specific claims made by Lord Maginnis. But he stressed that "the NIO takes its obligations under the Northern Ireland Act and Fair Employment legislation seriously".
He said: "There are also many pictures and portraits of Her Majesty, the Duke of Edinburgh and other members of the royal family on public display at Hillsborough Castle." Mr Smith said the NIO supported an extensive programme of visits by members of the royal family to Northern Ireland, "meeting many hundreds of people and a very wide range of groups from across all communities every year".
Ulster Unionist MLA Doug Beattie said as the head of state, a portrait of the Queen is a "symbol of sovereignty and not identity". "The Ulster Unionist Party respects the right of all our citizens to declare their identity to be British, Irish, or other; all should be respected equally. That was a core commitment in the 1998 Belfast Agreement, which enshrined the principle of consent," he said.
"The sovereignty issue was settled by public referendum in 1998 following the Agreement and given legal status by the Northern Ireland Act 1998.
"As Stormont House is the official residence of the Secretary of State for Northern Ireland, and HQ of the Northern Ireland Office locally, it is only fitting that portraits of Her Majesty should be on display there to both reflect and respect the constitutional reality of the sovereignty of the United Kingdom in Northern Ireland."
DUP Mid Ulster councillor Kyle Black, whose prison officer father David was murdered by the New IRA in 2012, tweeted a photograph of the unveiling of a portrait of the Queen by the artist Colin Davidson in 2016. The event in London was attended by Arlene Foster and former Deputy First Minister, the late Martin McGuinness.
"In light of recent events, this picture speaks volumes," Mr Black said. "Whilst opposing views are held on many issues, this shows a sense of respect and political understanding with a willingness to work together for the benefit of all in Northern Ireland."