Questions & Answers about Brúðkaupið er lítið en mjög fallegt.
Icelandic usually attaches the definite article as an ending instead of using a separate word like English the.
Brúðkaup is a neuter noun meaning wedding, and the neuter definite ending in the nominative singular is -ið.
So brúðkaup → brúðkaupið = the wedding.
Brúðkaup is a neuter noun.
Because the subject is neuter singular, the describing adjectives (lítið, fallegt) also have to be in the neuter singular nominative form.
That is why you see -t at the end of both adjectives.
The base form of the adjective is lítill (m.), lítil (f.), lítið (n.) = small.
Since brúðkaupið is neuter, you must choose the neuter form: lítið.
If the subject were masculine or feminine, you would use lítill or lítil instead.