It's not the usual international protocol.One would think a nation's leader would bring his own seal.
I remember back about 60 years when I was at the first meeting of the presidents of Perú and Ecuador in three decades. Despite the two nations being declared enemies, the two stands had the Ecuadorian seal on them. And the president of Perú stood behind one of them.
That was in the era in Ecuador when all business envelopes (including those of my stations) had to say "Ecuador was, is and will be an Amazonic country" after Perú had taken advantage of WW II to take about a third of Ecuador's eastern territory. And there was, constantly, shooting of each nations soldiers at the border areas. Still, the seal of Ecuador was on the Peruvian president's stand. Protocol.
(Those of us in the press at that meeting had a considerable fear that more resentful Ecuadorians would come in shooting at the Peruvians)