This post will continue to explore the topic by looking more deeply at the warning embedded in the commandment, then comparing the wording of the warning to Samuel the Lamanite's prophetic curse, and finally noting a similarity to a story found in Numbers 17-18.
The Warning
seek not after your own heart and your own eyes, after which ye use to go a whoring:
This will be your fringe. You will see it and remember all the Lord’s commands and do them. Then you won’t go exploring the lusts of your own heart or your eyes. (source)
'Exploring the lusts of your own heart or your eyes' is such a great way to describe a great variety of sins.
Samuel the Lamanite's prophecy
The wording of the warning reminds me of a part of Samuel the Lamanite's warning to the Nephites:
27 But behold, if a man shall come among you and shall say: Do this, and there is no iniquity; do that and ye shall not suffer; yea, he will say: after the pride of your own hearts; yea, walk after the pride of your eyes, and do whatsoever your heart desireth—and if a man shall come among you and say this, ye will receive him, and say that he is a . (Helaman 13)
Just a few verses later, Samuel prophecies their lamentation if they choose not to repent:
32 And in the days of your poverty ye shall cry unto the Lord; and in vain shall ye cry, for your desolation is already come upon you, and your destruction is made sure; and then shall ye weep and howl in that day, saith the Lord of Hosts. And then shall ye lament, and say:
33 O I had repented, and had not killed the prophets, and them, and cast them out. Yea, in that day ye shall say: O that we had remembered the Lord our God in the day that he gave us our riches, and then they would not have become slippery that we should lose them; for behold, our riches are gone from us. (Helaman 13)
Note the inversion -- when the covenant people welcome in those who tell them to walk after the pride of the hearts and eyes, they will become cursed and their wealth will be taken away from them, because they forgot that the Lord is the source of their riches.
Putting it all together
Here's where I arrive after all of this exploration: God recognizes the fickle nature of mortals and knows that without some safeguards, we are highly likely to sell ourselves "for that which has no worth" (2 Nephi 9:51). And so He mercifully offers an antidote. This is where the wordplay and symbolism come together and transform this strange commandment into something really beautiful. As discussed in part 1, the tassel ('zizith') of blue thread serves as a reminder of the head plate ('ziz') worn by the high priest and bearing the words "HOLINESS TO THE LORD." Combine this connection with the fact that both the word for tassel ('zizith') and the word for plate ('ziz') can have a floral connotation -- 'zizith' can refer to a 'floral projection' and 'ziz' can mean 'blossom.'
With this in mind, it is fascinating to then read on and come across the story of Aaron's rod just a few chapters later, in Numbers 17-18. After an act of rebellion on the part of some Israelites, Moses is commanded to take Aaron's rod and one from each of the other ancestral houses, write their names upon them, and place them in the tabernacle. The following day, a miracle is witnessed by all when Aaron's rod blossoms:
8 And it came to pass, that on the morrow Moses went into the tabernacle of witness; and, behold, the rod of Aaron for the house of Levi was budded, and brought forth buds, and bloomed blossoms, and yielded almonds. (Numbers 17)
Guess what root the word highlighted in green comes from? 'Ziz'! The same word that refers to the shiny gold head plate worn by Aaron as the high priest. Are the tassels then a symbol of life and increase, similar to Aaron's rod? Perhaps.
Conclusion
In order to protect us from the lusts of our eyes and hearts, God gives His children something holy to think about and be reminded of frequently, by commanding them to sew a reminder of heaven (blue), eternal increase and eternal life (tassels -- a representation of buds/blossoms) into the fringe of their clothing.
Eternal life is the greatest of all of God's gifts (see Doctrine & Covenant 14:7). Our own pride/lusts cause spiritual myopia that might allow us to be tricked into giving away our eternal birthright for a proverbial mess of pottage. God's wrath is directed at those things that cause us to forget He has in store for us.
18 For the of God is revealed from heaven against all ungodliness and unrighteousness of men ... (Romans 1)
To the extent that those distractions have entered our hearts and minds, we will perceive that His wrath is directed at us. But this is not so. God's wrath can best be likened to the feeling a parent might have toward a snake slithering up to their toddler. The closer the snake is to the child, the easier it might be for the child to misinterpret the parent's aggression.