Does a widely shared image show a nighttime photo of Mbabane, the capital city of Eswatini? No, that's not true: the city shown is Khartoum, the capital of Sudan.
The claim appeared in a Facebook post (archived here) on September 6, 2021. It features an image of a city at night with a caption that reads:
Goodnight 🌃 Africa, from the beautiful city of Mbabane, the kingdom of Eswatini 🇸🇿❤️
This is what the post looked like on Facebook on September 10, 2021:
(Source: Facebook screenshot taken on Fri Sep 10 17:02:56 2021 UTC)
This picture does not show Mbabane in Eswatini (formerly called Swaziland). Instead, it shows a view of Khartoum; in particular, the image features the city's Al-Shahid Mosque, which is more than 4,000 miles away from Mbabane, as seen in the embedded directions below:
(Source: Google Maps screenshot taken on Fri Sep 10 17:08:36 2021 UTC)
The image was originally taken by Hisham Karouri, a Sudanese photographer, and posted online in 2014. The image is included on his Instagram page here and his photography profile here (archived here). In the Instagram post, he uses the hashtags "#khartoum #sudan #bluehour #city_scape #karouri #nikon #nikond800 #sudanese_shoutout #sudanese_photographers #nile #nilestreet #corinthia."