Note that the front chimney of these two 055 is of the different design from Dalian, maybe actually 107 and 108
I think they are 105 & 106.
First of all, this photo was taken at Sanya. So they belong to the Southern Theater Command Naval Fleet.
If we zoom in, we can see a national flag on the top of the mast and a naval flag at the stern on both vessels.
PLAN flag:
The flags:
For Types 055s of the Southern Theater Command Navy they could be within the following ships: 105, 106, 107, 108.
The launching / commission date of the four ships:
105: 2018-7-3 / 2021-4-23
106: 2018-7-3 / not yet
107: 2019-12-27 / not yet
108: 2020-8-30 / not yet
According to Chinese naval tradition, uncommissioned warships would fly the national flag, but no naval flag. It's not very possible for 107 to enter service because it's just 20 months since it was launched. So even if 107 could be sailed to Sanya in a trial, it's not possible to fly a naval flag.
So it's most possible 105 & 106, in a condition when 106's commissioning order has been issued, but ceremony has not yet been held.