I believe the message here is:
KUDOS TO YOU!
The people in the images are:
US President John F. Kennedy,
Sprinter Usain Bolt,
Naturalist Charles Darwin,
Novelist George Orwell,
Father of psychoanalysis, Sigmund Freud,
UK Prime Minister Margaret Thatcher,
US politician Alexandria Ocasio-Cortez,
Cosmonaut Yuri Gagarin,
US President Barack Obama,
Novelist John Updike.
To read the hidden message:
for each picture, we need to take either the initial of the pictured person's first name or the initial of their surname. Doing this in a way that makes sense (and uses the hidden 'kudos' hint in the puzzle text) we can get:
John F. Kennedy, Usain Bolt, Charles Darwin, George Orwell, Sigmund Freud, Margaret Thatcher, Alexandria Ocasio-Cortez, Yuri Gagarin, Barack Obama, John Updike
In other words, this spells out KUDOS TO YOU!