The wave is like a woman in its physicality. The speaker of the text describes the wave as "tall and light." The wave "clutche[s]" at his arm and "[goes] off with [him] leaping." The wave seems to have the enthusiasm of a woman who is interested in a man. Just like a happy or contented woman might take the arm of the man she is with, the wave does similarly. The intimacy between the speaker and the wave is obvious and draws the "furious stares" of older people, much like public displays of affection between couples might. The wave disagrees with the speaker when he tries to explain to her that she cannot come to the city with him: "She cried, screamed, hugged, threatened." In short, she uses all of the emotional weapons at her disposal, and she manipulates him into getting what she wants.
After the speaker gets out of jail for "poisoning" the water on the train, he returns to his apartment and finds the wave there. He says,
Her presence changed my life. The house of dark corridors and dusty furniture was filled with air, with sun, with sounds and green and blue reflections, a numerous and happy populace of reverberations and echoes.
The wave is like a man's fantasy of a woman in that it makes his life happier, fuller, more exciting:
Even the abandoned corners ... were touched by her light hands. Everything began to laugh and everywhere shined.
This relationship seems so light and positive—at least for now—and the speaker feels that the sun literally shines on his life more fully now that the wave is there:
Love was a game, a perpetual creation. ... Her presence was a going and coming of caresses, of murmurs, of kisses.
This wave is beautiful and interesting and sexual, and there seem to be no downsides to it; in this way, it is like a male fantasy of a woman.