They mostly only carry their own brand with extremely limited options. If you want orange marmalade they have one style from one brand (their own). If you want some other style, find a different store. (This is the case with most of their items besides a small additional selection of eg certain candy, but still very sparse compared to other stores.)
Most items are set up in bulk on the cargo carriers it comes on. Although this is probably also a lot for show to give a "price consious" appeal.
They tend to have a significant part of the store dedicated to whatever random garbage they got a good deal on. Sometimes it's a boardgame, sometimes it's a stuffed animal, sometimes it's a power tool. Usually decent quality, but rarely the best.
For me I put Lidl in the class of store where you have to make multiple trips to different stores. If I'm cooking I can rarely go only to Lidl. You usually go there to buy some of the stuff you need but then get the rest at some other store with more items.