Talking about distinguishing between literature and credits, I need something similar.
So, an experiment: (not in mixing two styles, but in having two streams of information)
Using an extended author-title style as a base (ext-authortitle-ibid) to make things easier, and adding photographer and photoname as fields to use in an @photo bib entrytype, and using a counter to number the cited photos in sequence and printing that number as part of the citation (with a custom \photocite), and a corresponding bib driver (\DeclareBibliographyDriver{photo}), and using a keyword, "photo", to split the bibliographies, and remembering to reset the photocounter to zero just before the photo bibliography prints (and to keep the photo bibliography unsorted as well (via a refcontext) so it, too, is in citation order), we get:

MWEB
\RequirePackage{filecontents}
%dbx
%bbx
%cbx
%lbx
%bib
%ist
%:::::::::::::::::::::::::::::::::::::::::::::
\begin{filecontents*}{photo.dbx}
\DeclareDatamodelFields[type=field, datatype=literal]{
photoname,
photographer,
}
\DeclareLanguageMapping{english}{english-photo}
\endinput
\end{filecontents*}
%====================================
%:::::::::::::::::::::::::::::::::::::::::::::
\begin{filecontents*}{photo.bbx}
\ProvidesFile{photo.bbx}[2006/04/09 v1.0 biblatex bibliography style]
\RequireBibliographyStyle{ext-authortitle-ibid}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\DeclareBibliographyDriver{photo}{%
\usebibmacro{begentry}
\usebibmacro{photo-count}\addspace\usebibmacro{photoby-bib}
\usebibmacro{finentry}
}
\DeclareSortingTemplate{photosort}{
\sort{
\field{photographer}
}
\sort{
\field{photoname}
}
}
\newcounter{photonum}
\setcounter{photonum}{0}
\newcommand\incrphotonum{\refstepcounter{photonum}}
\endinput
\end{filecontents*}
%====================================
%:::::::::::::::::::::::::::::::::::::::::::::
\begin{filecontents*}{photo.cbx}
\ProvidesFile{photo.cbx}[2019-04-09 v1.0 biblatex citation style]
\RequireCitationStyle{ext-authortitle-ibid}
%~~~~~~~~~~~~~~~~~~~
% fieldformats: photo
\DeclareFieldFormat{photoname}{\mkbibquote{#1}}
\DeclareFieldFormat{photographer}{#1}
%~~~~~~~~~~~~~~~~~~~
% bibmacros
%======================= photoname
\newbibmacro{getphotoname}{%
\printfield{photoname}%
}
%======================= photographer
\newbibmacro{getphotographer}{%
\printfield{photographer}%
}
%======================= photoby-caption
\newbibmacro{photoby-caption}{%
\iffieldundef{photoname}{}{\usebibmacro{getphotoname}}%
\iffieldundef{photographer}{}{\addspace\mkbibparens{\usebibmacro{getphotographer}}}%
}
%======================= photoby-bib
\newbibmacro{photoby-bib}{%
\iffieldundef{photoname}{}{\usebibmacro{getphotoname}}%
\iffieldundef{photographer}{}{\addcomma\addspace\bibstring{photoby}\addspace\usebibmacro{getphotographer}\isdot}%
}
\newbibmacro{photo-count}{%
\incrphotonum\mkbibbrackets{\thephotonum}
}
%~~~~~~~~~~~~~~~~~~~
% citecommands
%======================= photocite
\DeclareCiteCommand{photocite}%
%@@@@@@@@@@@@@@@@ prenote
{%
\usebibmacro{prenote}%
}%
%@@@@@@@@@@@@@@@@ item
{%
\ifentrytype{photo}%
{%photo ==================================
\usebibmacro{photo-count}\addspace\usebibmacro{photoby-caption}%
}{}}%
%@@@@@@@@@@@@@@@@ delim
{}%
%@@@@@@@@@@@@@@@@ postnote
{%
\usebibmacro{postnote}%
}
\endinput
\end{filecontents*}
%====================================
%====================================
\begin{filecontents*}{english-photo.lbx}
\ProvidesFile{english-photo.lbx}[2019/04/09 english with additions for photo citations]
\InheritBibliographyExtras{english}
\NewBibliographyString{photoby}
\DeclareBibliographyStrings{%
inherit = {english},
photoby = {{photo by}{photo by}},
}
\endinput
\end{filecontents*}
%====================================
%====================================
\begin{filecontents*}{\jobname.bib}
@photo{ph1,
photoname={The Woods},
photographer={M Woods},
keywords={photo},
}
@photo{ph2,
photoname={The Sky},
photographer={A B Skier},
keywords={photo},
}
@photo{ph3,
photoname={The Air},
photographer={O Ayre},
keywords={photo},
}
@photo{ph4,
photoname={The Lake},
photographer={N Lakes},
keywords={photo},
}
@photo{ph5,
photoname={The Sea},
photographer={R Seasons},
keywords={photo},
}
\end{filecontents*}
%====================================
\documentclass[12pt]{article}
\usepackage{fontspec}
\setmainfont{Noto Serif}
\usepackage[british]{babel}
\usepackage{csquotes}
\usepackage[
style=photo,
]{biblatex}
\defbibnote{abibnote}{Plain bibliography}
\defbibnote{photobibnote}{List of photos}
\usepackage{xcolor}
\pagecolor{red!3}
\addbibresource{biblatex-examples.bib}
\addbibresource{\jobname.bib}
\begin{document}
\section{Introduction}
Some plain cites:
\cite{kastenholz}
\cite{vangennep}
Some photo cites: air: \photocite{ph3}, sky: \photocite{ph2}, and sea: \photocite{ph5}.
\printbibliography[prenote=abibnote,notkeyword=photo]
\setcounter{photonum}{0}
\newrefcontext[sorting=none]
\printbibliography[
keyword=photo,
title={Photos},
prenote=photobibnote,
]
\begin{center}
\textemdash
\textemdash
\end{center}
\end{document}
Being able to classify the data into categories is key: entrytype and keyword help here (and also category, for that matter). The information could even be stored in, say, the @article entrytype with appropriate use of \ifentrytype and ifkeyword (manual: 4.6.2 Stand-alone Tests, at p 233). There is also an entrysubtype available, for even greater granularity.
Printing the citations rotated sideways (and/or as part of captions) is also possible.
On a different solution path, different bib environments (to define what gets printed as the lookup label) combined with different sorting schemes is another methodology, since bibliographies are "just" list environments.