How does she resemble a date tree?
Tanchuma (Bamidbar 15): This refers to Shevet Levi. Just like a date tree has only one heart, so Shevet Levi has only one heart for Hashem. "va'Yomer Moshe Mi la'Shem Elai va'Ya'asfu Elav Kol Bnei Levi" (Shemos 32:26).
Rashi: We saw the beauty of your height in the days of Nebuchadnetzar. All the nations bowed and fell in front of the image, and your stature was erect like a date tree.
Seforno: "Komasech" is your level. It is very high, like a date tree. Great exertion is needed to get its fruit. This nation, its fruit is sparse, without scent. Its food is not nice. So the heads of your nation exercised authority over the Tzibur, even though they gave fruit without much benefit.
Malbim (Melitzah): After all aspects of the body and its powers argued with the Nefesh that it should not separate from them, and each requested by itself, for via this it will perish, ha'Melech Shlomo himself (the heart, the source of life, beats until death) departs from his beloved, the Nefesh. It is aroused with all its strength to stop the Nefesh from departing 1 . He tells his Nefesh, all the details until now, from "Mah Yafu Fe'amayich" (2) until the head, is the stature of the Heavenly beloved. The Nefesh ha'Tzomachas, Chiyunis and intellectual comprise its full stature. These powers will depart from it. It is like a date tree - it sprouts upward and its heart faces up. So you face up, and your desire is to your Husband in Shamayim!
Malbim (Mashal): Ha'Melech Shlomo himself speaks to her - now you stand erect with pride and strength, like a very tall date tree.
Malbim: It is known that at the moment before death, the heart is invigorated with all its strength.
How do her breasts resemble clusters?
Rashi: Daniel, Chananyah, Misha'el and Azaryah, who were like breasts for you to nurse from them, were like clusters, that produce beverages. So they influenced to nurse (give milk) and teach everyone that there is no fear like your (Yisrael's) fear [of Hashem].
Seforno: The breasts are those who teach the nation. They are like date clusters. There are many dates and little benefit. So they found Chachmos of little benefit, like the conversation of date trees and parables of launderers (Sukah 28a).
Malbim (Melitzah): The clusters already ripened the grapes and they are ready to be harvested and put in winepresses to extract their wine. So came your time of 'harvest' to depart from this world and receive reward for your deeds in the world of payment.
Malbim (Mashal): They hang from her height, like clusters.
