Zimmer was viewed as a bit of a Stanford hitter last Summer. For those that don't know Stanford has a long history (and it works for them) of developing hitters with fairly flat swings and not much power. Same was true of Zimmer (of nearby U of San Francisco), a 6'5" 205 lb Left handed hitter and the younger brother of Royals prospect Kyle Zimmer. Zimmer is an interesting prospect and while I don't think he's a likely pick at #7, the Phillies mine California as much as anyone and the system is literally littered with top picks from Southern Cal (Dugan, Watson, Crawford all the way back to Utley and Hamels). In fact it's the top picks not from California where the Phillies have had more issues (Hewitt, Greene, Savery, Drabek all the way back to Cardenas and Golson).
You may hear Zimmer referred to as a five-tool prospect and he kinda, sorta is. You hear 5-tool and think "Oh, this guy is awesome across the board." Zimmer more slightly above average across the board with a few tools that could be plus. First off, Zimmer is stupid fast for a guy his size. Certainly above-average, could be plus. That speed will be enough to allow him to play Center Field at the next level. He also has an above-average to plus arm that could allow him to play either Right or Center. He should be an above-average defender in either spot, so that just leaves hitting.
Zimmer, as can be seen in the video below from 2013 (courtesy of rkyosh007) Zimmer has a very flat, line drive swing that keeps his bat in the zone for quite a while. His bat speed is good, but not great and he shows good patience at the plate, but he'll bite and chase breaking balls leading to weak contact. Of course this video is a year old and Zimmer is suddenly putting up big power numbers, so let's see if there's a more recent video.
This next video is incredibly short (courtesy Perfectgamebaseball), but it's very current and looks more like his BP swing in the first video with more uppercut.
I wish there was more current video. The reports on him in 2014 indicate a guy who could develop plus power, last year, he looked more like a guy who would hit a few, but was probably going to be more of a Doubles hitter. I'm not enamored with his hit tool overall, but it has a chance to be average or slightly above average. His skill set and build is pretty similar to Aaron Altherr and I actually think he has a similar ceiling to Altherr. Zimmer is the kind of guy I could see the Phillies being interested in, but I'd be surprised if they were interested at pick #7.