I'm assuming that you can, but unlike the premium gachas, there's no button that lets us see the contents, so I was wondering what 4-stars other people have gotten from the machine. 4-stars I've seen from the free machine so far:

4 - Yulan
3 - Cepha Lanthera
2 - St. Paulia
2 - Cyani Cornflower
1 - Violetta Tulip
1 - Snowflake
1 - Dandelion

I'm mostly bothered that I haven't gotten any pierce units yet, but it's probably just RNG (not to mention there are fewer pierce 4-stars). Also, has anyone gotten the new 4-star in the free gacha? I'm not sure if she's in the free gacha if she hasn't even been added to normal premium gacha yet.