The chair emoji (ðª) is just a substitute for the laughing emoji (ð). It has no deeper meaning.
The trend originated from a now-deleted tiktok that said "if you're seeing this, you're a part of an inside joke. From now on, let's all just start using this:ðª instead of this: ð when something is funny."
"LMAOO ðªðªðªðªðª"
description: "LMAOO (chair emoji) (chair emoji) (chair emoji)"
-Translation-
"LMAOO ððððð"
description: "LMAOO (laughing emoji) (laughing emoji) (laughing emoji)"