Korovin's stylistic sketchiness seemed to kick into a higher gear following his move to France in 1923. Perhaps this had to do with the need to quickly produce paintings to bring in money. Or maybe it had to do with Paris being an avant-garde artistic place (though the same might be said for Russia, especially in the early post-Revolution years). Or it could have been that this was his natural artistic trajectory as he continued to gain maturity and experience. And, possibly, this looser style was what the Paris art market wanted, so he supplied it.
Below are examples of Korovin's work. I essentially skipped over his earlier landscape paintings, but they and others can be found by Googling.
Russia's main White Sea port.
Morosov was an art collector.
The famed opera singer.