Chips on the front of the motherboard:

Samsung K3RG2G20BM-MGCJ 4 GB LPDDR4 mobile DRAM with a quad-core Qualcomm Snapdragon 821 processor layered underneath (two cores clocked at 2.15 GHz and two cores clocked at 1.6 Ghz)

Qualcomm PMI8996 power management IC, and Qualcomm SMB1350 Quick Charge 3.0 IC

NXP TFA9891 smart audio amplifier

Qualcomm WTR4905 LTE RF transceiver

3207RA G707A (looks like Wi-Fi)

NXP 55102 1807 S0622 (likely NFC controller)

Bosch Sensortec BMI160 low power IMU