A portrait of Princess Diana was moved from a prominent position at Cardiff City Hall as Prince Charles visited with his new wife.
The portrait of Princess Diana was painted by John Merton
The painting, which shows Diana in three poses, was taken from the top of a staircase and put in a corridor.
The prince toured with the Duchess of Cornwall as part of their Welsh tour.
Cardiff Council said pictures' position often changed, and it allowed the showing of royal charters marking 100 years as a city and 50 as a capital.
The picture, which had hung in the Marble Hall for many years, has been moved to a nearby corridor.
A spokesman for the council said: "Pictures and portraits are often changed around the Marble Hall.
"The two paintings, the (Diana) portrait and the painting Winter, which are being moved will allow us to display the royal charters concerning the declaration of Cardiff as a city and a capital of Wales that directly relates to the celebratory event on Thursday.
"As City Hall is a site protected by (the Welsh historical monuments body) Cadw, we are not allowed to drill into untouched walls.
Council leader Rodney Berman said it was an "operational matter"
"So we can only alter displays by switching paintings and portraits around other sites within City Hall," he added.
And his comments were echoed by the council leader Rodney Berman who said: "It was simply an operational matter, we periodically move the portraits around City Hall and on this occasion we thought it would be very nice to display the royal charters which were granted to Cardiff when it became a city in 1905."
And when asked what he thought of any criticism about moving the portrait he replied: "I think if we hadn't moved the portraits someone might equally have come along and criticised and said leaving it up could have been insensitive."
Prince Charles and the Duchess of Cornwall were at City Hall on their final day of their three-day Welsh tour.
A spokeswoman for Clarence House said the move was not made to spare any blushes. She said: "The original route that we were going to take would still have gone past the picture in its new position."
"It is not an issue, we are not trying to hide from it.
"There are pictures of Diana all over Wales, she was the Princess of Wales after all."
The prince, who visited the building in 1969 to receive the freedom of the city, made a speech in the council chamber praising the city's "energy and optimism".