Arthurk's explanation is correct.
The 2 marriage ceremonies practice was more common pre-1837 and post-1908.
Catholics had to marry in Anglican churches until 1837 to comply with the law but some also had a Catholic ceremony which was purely religious.
Between 1837 and 1908 Catholics in England had choices of marrying in a Catholic church (or even a Non-conformist chapel as one of my ancestors did in a hurry) with a registrar present, marrying in C. of E., or having a civil ceremony with or without a separate ceremony in a Catholic church. Any of those options satisfied the law and the Catholic Church in England.
Other countries had their own marriage laws and the Catholic Church in each country complied with them, occasionally issuing a papal encyclical on marriage. For instance a marriage which took place in Ireland between a Catholic and a member of Church of Ireland for much of C19th had to be in C. of I. or registry office to be legal but a marriage between 2 Catholics in a Catholic church in Ireland was legal.
The situation changed after the encyclical on marriage which was known as "Ne temere" in 1907. This regulated marriage of practising Catholics worldwide, replacing the practices in individual countries and even individual dioceses. It was prompted in part by increased emigration and internal migration and difficulty in knowing whether a person wishing to marry was free to marry or had a living spouse elsewhere.
"Ne temere " came into effect at Easter 1908. A Catholic was required to marry in the presence of a Catholic priest (parish priest or someone acting with PP's authority), usually in the bride's parish. Information about the marriage was to be recorded in the baptism register of the parish where the spouses were baptised, although this didn't always happen.
I've noticed an increase in double marriage ceremonies in the decade 1910-1920 in the Catholic parish of Bacup, Lancs. Priest noted place & date of previous marriage ceremony. Proportion of mixed marriages in the parish was high at the time. Some couples who had a 2nd wedding at that church had their 1st wedding in registry office or C. of E. during WW1 or when bride was pregnant. Months or years might elapse between the 2 weddings. I deduce from it that 1st ceremonies may have been arranged for speed and simplicity.