Either one is fine.
For some reason though, for the first three days I have baby chicks I put food all over the floor of their cage. I am always so worried about making sure that all of them are eating and drinking. This time I also fed them some grow gel stuff and that I put on a small plastic sheet.
In addition to sprinkling feed all over the floor, I use a feeder like your second picture, the long one, but I take off the top for the first few days. Yes, I know that means they walk and even poop in the feed, but I clean that out.
