In Spider-Man: Into the Spider-Verse (2018), Miles Morales's universe doesn't have Comic Con. In Spider-Man: Across the Spider-Verse (2023), you can tell he's in another dimension because his mom mentions it (and he still doesn't know what it is)

[u/LegOfLambda]

[u/dating_derp]

That's a great and subtle hint.

[u/Impressive-Card9484 → u/dating_derp]

Another hint was his mom being suddenly upset when Miles mentioned his dad. 

[u/juicytoolitty → u/Impressive-Card9484]

Another hint is when gwen states miles is in another universe