Mixed feelings, voted no.
Something to note, if you aren't familiar with the situation:
GGG is against d2jsp usage and people have been banned for it.
There was a previous trophy room, but it was removed.
While recent
polls indicate a desire for a trophy room, the comments in the poll thread are flipped in percentage of negative vs positive opinions

I'm going to quote myself on some previous reasons I laid out earlier this year.
Quote
- 1. GGG, unlike Blizzard, still bans people for using d2jsp when reported or when certain word filters are hit. Showing notable items you have will attract attention that can and has resulted in bans in recent months. There is also an indexing service that contains almost every item, letting just a rare item name, base and a single stat identify the current account of the seller of that item.
- Counter argument: The same risks are taken while trading, and this is voluntary, what's the difference?
- Response: When trading, users can simply post text of their item or a description, and so if GGG decides to look at a user and topic they believe are tied to an account, they can't really tell if the poster is the owner, or someone who copy pasted their item data from a shop. However, in a trophy scenario, it's absolutely necessary to prove you own the item, so a proper screenshot, which proves ownership, is required.
- 2. Unlike D2, top tier rare items are not one-of-a-kind. Truly trophy worthy items are mirrored. If you're posting a screenshot of a mirrored item, then it isn't a trophy, because several of the exact same thing exist. If you're posting the original, then due to the popularity of mirror services, you'll be identified in minutes. See #1
- Counter argument: What if we restricted it to non-mirror worthy items, in default leagues?
- Response: Then we've made it not a trophy room anymore
- Counter argument: What if it was restricted to temp leagues?
- Response: Not a bad idea really.
- 3. It's gonna cause drama. OP will post an item, people will them pretty harshly that it isn't, OP gets mad, back and forth, etc. Like the D2 forums, except that the difference in what is considered a great item varies even more per league/core, relative to D2, trophies in default HC have far lower standards than default Softcore-- a 5 exalt item may be considered a trophy to many users, while others visualize 100 exalt+ trophies. Etc
- Counter argument: We have mods that can settle arguments!
- Response: Right, but the quality of an item is subjective, so while slap fights can be discouraged, it's hard to visualize a system where it doesn't end up as a permanent +1/complaining sub. You can't punish someone for posting borderline not-trophy items and causing whining, because it's an opinion. I'd be personally a lot more open to it if we had an official layout of planned rules/standards to talk about before the sub is created. But because of #1 and #2, still a definite no.
It's a nice idea, but it isn't for path of exile.