I've shown the holographic United Nations stamp before, so today it is the turn o two of the other stamps on this envelope.
The rose is a 1c definitive stamp issued in 2009, and the rhino was issued to coincide with the 17th meeting of the Conference of Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. This meeting, abbreviated to CITES CoP17, was held in Johannesburg, South Africa, in 2016.
My scanner must have been acting up, so sorry about the grey lines. I will try and get a better scan in a few days. In the meantime, here is the minisheet this stamp came from, highlighting endangered African species, with the subtitle, Eye on Africa. A nice touch is the outline of the African continent placed at the center of the minisheet.