These are called Matryoshka Dolls, Nesting Dolls or Stacking Dolls. Five pieces doll has very rare kind of the painting. Each doll is richly decorated by round painting.
The birds are accurately painted with help of Lacquer miniature technique. The artist has painted each doll with extreme life-like detail and expression.
In work the artists used tempera with egg emulsion and fine polecat brushes. Very rich and bright paints are used. The parrots are painted so vividly that looks like alive.