How to mount an Android 4.4.4 in USB mass storage device mode?

I'm trying to mount Android phone (Lenovo P70-A) to recover deleted files. Phone is detected in lsusb and dmesg. Last command prints

usb-storage 1-3:1-0: USB mass storage device detected ...
sd 2:0:0:0: [sdb] Attached SCSI removable disk

/dev/sdb has appeared, however the device isn't shown in lsblk.

Just mount returned error:

> sudo mount /dev/sdb /media/lenovo
> mount: no medium found on /dev/sdb

I managed to mount it with specific filesystem types (mount ... ... -t <fs-type>) as bpf, cgroup2, cpuset, devpts, devtmpfs, fuse, fusectl, hugetlbfs, mqueue, pstore, proc, securityfs, sysfs, tmpfs but they contain system files or just nothing. Btw device still wasn't in 'lsblk'. Such types as ext2, ext3, ext4 and vfat gave the same errmsg "no medium...".

My aim is to recover deleted photos and videos so what should I do?

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