"Selfie Arm" solves this problem. It was jointly developed by artists Aric Snee and Justin Crowe.
"Selfie Arm" is a selfie stick that realistically reproduces the human elbow to fingertips. Attach a smartphone etc. to the elbow part and hold the hand part to take a picture. Then, in the captured image, another arm (likely thing) is reflected in addition to myself, and it is a mechanism that pretends to be traveling together.
One of the co-developers, Justin Crowe, recommends creating a dedicated SNS account for "Selfie Arm." After uploading the images taken with "Selfie Arm" to your SNS, like it from your "Selfie Arm" account. This allows you to get at least one like, even if you don't have any friends. And Crowe argues that it's not a self-made performance. The "Selfie Arm" just liked it, not you.
The material is glass fiber. It's a lot lighter than it looks, and even if you take a few photos, your hands won't get tired. The artist also claims that it is easy to carry.
That said, the "Selfie Arm" is so realistic that many would be scared if it sticks out of the bag. If it is found during baggage inspection at the airport, the explanation can be quite annoying.
Snee and Crowe sell autographed prototypes (limited to 10). The price is 6,200 dollars (about 740,000 yen). If you want it, please contact Eric Snee.