I think that's sort of part of it, but I think it's at least as much about the people in the houses as the ornaments on the lawns, who I see as likely representations of a Boomer (an actual boomer, not merely "someone older than me") on the right and a gen-x on the left.

• The woman in the house on the right has a very particular style of someone who connects to the late 50s, which were formative years for boomers. I don't know when this strip was published, but the heyday of Far Side was the late 80s... so I'll assume then. This 50s look is a style, but also mindset. That's an old lady staring out of her window, and gripping onto a certain feeling of the past.
• Lawn flamingos were apparently first created in '57 and became popular kitsch on middle class lawns but then in the mid-80s apparently there was a revival of Florida kitch driven by the popularity of the Miami Vice TV show: https://daily.jstor.org/how-the-plastic-pink-flamingo-became-an-icon/ so there might be a sort of reference to then-current events going on with this revival of trashy lawn garbage... though to me it's notable that it was very clearly a revival calling back to the 50s when it happened in the 80s. But either way, that woman is sort of reflecting her cultural identity out on her lawn. The right side of this image is a sort of visual OK Boomer.
• The identity of gen-x, especially in the 80s was less clearly defined and much less homogeneous. And weirdness was a part of it, like the difference between Frank Sinatra (notable boomer) and Frank Zappa (notable x'er). I think this weirdness reflects in Far Side itself as well, which is much more obtuse than Peanuts or other comics/media giants of the 50s and 60s. But in the 80s it was still pretty odd to broadcast your brand of weirdness outside your close circle of friends. That dood on the left might be a closet expert in spiders and snakes, and might talk about them incessantly with his friends, but in real life broadcasting that identity would be considered very strange. You'd have been fine until you put the lawn ornaments up, and now your flamingo neighbors are looking at you weird.

So anyhoo, I see this as a bit of a generational commentary, a bit of a commentary on asymetric identity broadcasting, wrapped up in a sort of a visual pun that just feels absurd. That's of course a mountain of speculation, and perhaps a mirror of my own biases as much as a read of Larson's intent... but this stuff would have been floating around in the cultural broth Larson was cooking with, and it a read that's not all that out of character for his style.