During their long stay in Egypt, the Israelites experienced a profound spiritual decline. The nation is portrayed as young women, using the imagery of prostitution as an allegory for idolatry and spiritual betrayal against God [רד״ק]. This spiritual downfall stemmed from a combination of factors. Egypt was a corrupt environment filled with abominations. The Israelites, in their national youth and before receiving the Torah, lacked spiritual maturity and acted with recklessness. Furthermore, the Egyptians actively tempted and misled the people into adopting their customs [מלבי״ם].
The physical imagery of inappropriate touching and pressing represents the preliminary stages of an illicit relationship. Conceptually, this illustrates that while the Israelites began to involve themselves with Egyptian idols, their involvement was only partial. It is viewed as the mere beginning of a sin rather than a complete act of idolatry [מצודת דוד, ביאור שטיינזלץ]. Because their participation in idol worship was largely unintentional, God did not hold them fully accountable for the complete sin, which is why the imagery reflects only the initial steps of wrongdoing [חומת אנך].
The active physical manipulation in the metaphor also symbolizes the aggressive way the Egyptians taught the Israelites their practices, deeply embedding a corrupt culture into the nation [רש״י, רד״ק]. On a deeper allegorical level, the physical features mentioned represent the Commandments and the rich spiritual heritage the Israelites received from their ancestors. The violation of these features symbolizes the abandonment of these Commandments and the nation's tragic distancing from its sacred tradition under the heavy influence of Egyptian society [רד״ק].