According to their form - Rather, “after their manner” (compare 2 Chronicles 4:20). There is no allusion to the shape of the candlesticks, which were made, no doubt, after the pattern of the original candlestick of Moses.
SDA Bible Commentary (limited)
Volume 1-7
7. Candlesticks. Compare 1 Kings 7:49; Jer. 52:19. There were ten candlesticks in Solomon’s Temple. Perhaps the ten were in addition to the original candlestick of the tabernacle (Ex. 25:31-39; Ex. 37:17-24). Whether or not they were patterned after it is not stated.