^^Where you asked "what's this?" is the Jean Gang twisty tower (400 ft) on Folsom:
http://forum.skyscraperpage.com/showthread.php?t=212226
SF may get a 450 ft tower on the temporary TransBay Bus terminal plot at the end of the block on Howard directly across the street from the Park Tower--pretty much where your circle is. It is zoned for such. The rest of the block is going to be developed as a combination of midrise, lowrise and a park which that neighborhood will need. The folks in all those towers need a place to walk their dogs and play "catch".
https://sf.curbed.com/2013/8/15/1020...nsbay-terminal
Both sites you have questions about are actually seen in this rendering with the park in the foreground and the Jean gang tower in the background:
http://www.socketsite.com/archives/2...inal-site.html
The massing with a "?" is a 160 ft condo structure, actual design as yet unknown along the Folsom St. end of the block. There was 4 years between these 2 renderings (the top one is oldest) and I'm not sure if the 160 ft condo was part of TransBay height rezoning or if the earlier rendering just doesn't show its height very well. The actual designs of all these buildings on the temporary terminal block is still very tentative and, as far as I can determine, no developers have been selected for them.
I guess all this belongs in the "City Compilations" section.