If you want an iPhone mini sized Android phone, you'll probably have to make some serious trade-offs.

According to Wikipedia, the iPhone mini is 131.5 mm tall and 64.2 mm wide. Using the "Phone Finder" on GSMArena, the closest phone dimension-wise, released in 2021, is the Alcatel 1 (137.6 x 65.7). Of course, it runs Android 11 Go because it only has 1GB of RAM. There are also a couple of Samsungs (A01 and M01 Core) at 141.7 x 67.5, but they only go up to 2GB and run Android 10 Go.

So it doesn't look like there are any "premium" Android phones that are close in size to the iPhone mini. Which is a shame.