Thanks for the feedback. I’m always torn between which way to put those sorts of icons but this appears to be the most widely used and recommended approach so I’ve gone with that to start with. I’m assuming that because this type of interface is so inconsistent across all devices and applications, users just have to get used to the specific way that one individual app works but this is clearly not ideal.
It would be interesting to perform or see some results from user studies relating to the various combinations of arrow directions to see if there is any new consensus forming among users, and whether a user’s opinion of which way they should be orientated is influenced by factors such as what devices they use most frequently or were brought up using at a young age.