From Yokohama, Japan. The stamps are from a set of five marking the 50th anniversary of the return of Okinawa to Japanese control. The stamp on the left represents the culture and entertainment of Okinawa and the stamp on the right represents its history. The US occupied the islands after the end of the Second World War and maintained control of them until 15 May 1972.
From the Hong Kong town of Ma On Shan. The stamp on the left shows the small island Po Pin Chau on the eastern edge of Hong Kong. And the two on the right are 2022 stamps from a set commemorating the third anniversary of the ambitious Guangdong-Hong Kong-Macao Greater Bay Area Outline Development Plan. The goal is to integrate these cities around the bay into one large business hub. The area already accounts from something like 12% of China's GDP and 37% of the country's exports.
I know it's from somewhere near Athens but I can't make out the postmark to know exactly. The stamp on the left is a Dusky Grouper from 2012 and on the right is an anti-bullying stamp from 2020. I believe this one specifically deals with social isolation.
From Germany. The postmark commemorates Antarctic explorer Ernest Shackleton. Shackleton died of a heart attack on 5 January 1922 in South Georgia at the start of the Shackleton–Rowett Expedition. The stamp on this cover was issued in 2001 and shows an image of the RV Polarstern: Germany's polar research vessel.
FDC postmark on a Polar Lights stamp from Germany. Specifically the Northern Lights over Lofoten, Norway. It is the latest stamp in a series that feature celestial events. The 5c definitives on the left are waterlilies but if you look closely you'll notice the flowers are actually made of letters and pencils. Smart. All are 2022 stamps with new matrix codes.
