Fucking hell OP - you must be regretting inadvertently starting this one-upmanship parade of arseholery but it’s very entertaining for the rest of us 😂.
The dress looks quite stiff, but if you like the structure of it and it feels comfortable, I’d say it’s perfectly appropriate - although the fact it’s midi and you describe it as ankle length does make me wonder, like other PPs, if it fits you properly? Maybe look at some of the petite ranges of evening wear?
There’ll almost certainly be a mix of nice day dresses and more glam evening wear if it’s black tie, but for the majority of the population who aren’t balls-deep in Debretts and sneery ‘gauche and tacky’ judgements, it just means ‘make a special effort to look nice and dress for a party’. And you’ll have a better time if you’re feeling confident and comfortable, so if you love the dress, go for it.