This problem is symbolic - here the main actor in the play is white Queen (Julia!) which demonstrates a super activity: makes 7(!) different moves in the two variants in three different roles: a) Realized the thematic try and the key; b) realized block by the black Pawn; c) realized the block of white square around the w.King.
Systematic play of two black Pawns which creates with help of the w.Queen two chameleon-echo model mates. Change of block-pieces on the thematic "Immun - squares" e7/f7
Umnov-theme ; a) black Umnov - after moves 4...f4 5.Rf5! and 4...e4 5.Re5! respectively; an other Umnov after moves: 4.Qd2! f4 and 4. Qg2! e4 respectively; b) white Umnov after 5.Rf5 &6.Bf7! and 5. Re5&6.Se7! respectively.
The super-actrivity by the w.Queen is combined also with specific and paradoxical Rooks moves during the lines "e" and "f".