Can someone tell me what this icon is and how or if I can access it. I'm playing on PS4.

Greetings Jessead82!

This is the new Item collection UI that was December of last year.

To move the UI you can check the UI re-organizing option via the "Edit UI" tab (RT first Icon for Xbox or R2 first Icon for PlayStation).

To adjust the Item collection level you can navigate to the "Adventure Tab" and then select "Item collection Increase Scroll", from there you're able to select the levels so long you have Item Collection Increase Scrolls in your inventory. You may also decativate it from this window & are able to assign this setting to your ring menu for quicker use.

Hope this helps.